TY - JOUR A1 - Zoccarato, Luca A1 - Sher, Daniel A1 - Miki, Takeshi A1 - Segre, Daniel A1 - Grossart, Hans-Peter T1 - A comparative whole-genome approach identifies bacterial traits for marine microbial interactions JF - Communications biology N2 - Luca Zoccarato, Daniel Sher et al. leverage publicly available bacterial genomes from marine and other environments to examine traits underlying microbial interactions. Their results provide a valuable resource to investigate clusters of functional and linked traits to better understand marine bacteria community assembly and dynamics. Microbial interactions shape the structure and function of microbial communities with profound consequences for biogeochemical cycles and ecosystem health. Yet, most interaction mechanisms are studied only in model systems and their prevalence is unknown. To systematically explore the functional and interaction potential of sequenced marine bacteria, we developed a trait-based approach, and applied it to 473 complete genomes (248 genera), representing a substantial fraction of marine microbial communities. We identified genome functional clusters (GFCs) which group bacterial taxa with common ecology and life history. Most GFCs revealed unique combinations of interaction traits, including the production of siderophores (10% of genomes), phytohormones (3-8%) and different B vitamins (57-70%). Specific GFCs, comprising Alpha- and Gammaproteobacteria, displayed more interaction traits than expected by chance, and are thus predicted to preferentially interact synergistically and/or antagonistically with bacteria and phytoplankton. Linked trait clusters (LTCs) identify traits that may have evolved to act together (e.g., secretion systems, nitrogen metabolism regulation and B vitamin transporters), providing testable hypotheses for complex mechanisms of microbial interactions. Our approach translates multidimensional genomic information into an atlas of marine bacteria and their putative functions, relevant for understanding the fundamental rules that govern community assembly and dynamics. Y1 - 2022 U6 - https://doi.org/10.1038/s42003-022-03184-4 SN - 2399-3642 VL - 5 IS - 1 PB - Springer Nature CY - Berlin ER - TY - JOUR A1 - Bizic, Mina A1 - Ionescu, Danny A1 - Karnatak, Rajat A1 - Musseau, Camille L. A1 - Onandia, Gabriela A1 - Berger, Stella A. A1 - Nejstgaard, Jens C. A1 - Lischeid, Gunnar A1 - Gessner, Mark O. A1 - Wollrab, Sabine A1 - Grossart, Hans-Peter T1 - Land-use type temporarily affects active pond community structure but not gene expression patterns JF - Molecular ecology N2 - Changes in land use and agricultural intensification threaten biodiversity and ecosystem functioning of small water bodies. We studied 67 kettle holes (KH) in an agricultural landscape in northeastern Germany using landscape-scale metatranscriptomics to understand the responses of active bacterial, archaeal and eukaryotic communities to land-use type. These KH are proxies of the millions of small standing water bodies of glacial origin spread across the northern hemisphere. Like other landscapes in Europe, the study area has been used for intensive agriculture since the 1950s. In contrast to a parallel environmental DNA study that suggests the homogenization of biodiversity across KH, conceivably resulting from long-lasting intensive agriculture, land-use type affected the structure of the active KH communities during spring crop fertilization, but not a month later. This effect was more pronounced for eukaryotes than for bacteria. In contrast, gene expression patterns did not differ between months or across land-use types, suggesting a high degree of functional redundancy across the KH communities. Variability in gene expression was best explained by active bacterial and eukaryotic community structures, suggesting that these changes in functioning are primarily driven by interactions between organisms. Our results indicate that influences of the surrounding landscape result in temporary changes in the activity of different community members. Thus, even in KH where biodiversity has been homogenized, communities continue to respond to land management. This potential needs to be considered when developing sustainable management options for restoration purposes and for successful mitigation of further biodiversity loss in agricultural landscapes. KW - agriculture KW - eRNA KW - land use KW - metacommunity KW - transcriptomics Y1 - 2022 U6 - https://doi.org/10.1111/mec.16348 SN - 0962-1083 SN - 1365-294X VL - 31 IS - 6 SP - 1716 EP - 1734 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Huang, Lixing A1 - Qiao, Ying A1 - Xu, Wei A1 - Gong, Linfeng A1 - He, Rongchao A1 - Qi, Weilu A1 - Gao, Qiancheng A1 - Cai, Hongyan A1 - Grossart, Hans-Peter A1 - Yan, Qingpi T1 - Full-length transcriptome BT - a reliable alternative for single-cell RNA-seq analysis in the spleen of teleost without reference genome JF - Frontiers in immunology N2 - Fish is considered as a supreme model for clarifying the evolution and regulatory mechanism of vertebrate immunity. However, the knowledge of distinct immune cell populations in fish is still limited, and further development of techniques advancing the identification of fish immune cell populations and their functions are required. Single cell RNA-seq (scRNA-seq) has provided a new approach for effective in-depth identification and characterization of cell subpopulations. Current approaches for scRNA-seq data analysis usually rely on comparison with a reference genome and hence are not suited for samples without any reference genome, which is currently very common in fish research. Here, we present an alternative, i.e. scRNA-seq data analysis with a full-length transcriptome as a reference, and evaluate this approach on samples from Epinephelus coioides-a teleost without any published genome. We show that it reconstructs well most of the present transcripts in the scRNA-seq data achieving a sensitivity equivalent to approaches relying on genome alignments of related species. Based on cell heterogeneity and known markers, we characterized four cell types: T cells, B cells, monocytes/macrophages (Mo/M phi) and NCC (non-specific cytotoxic cells). Further analysis indicated the presence of two subsets of Mo/M phi including M1 and M2 type, as well as four subsets in B cells, i.e. mature B cells, immature B cells, pre B cells and early-pre B cells. Our research will provide new clues for understanding biological characteristics, development and function of immune cell populations of teleost. Furthermore, our approach provides a reliable alternative for scRNA-seq data analysis in teleost for which no reference genome is currently available. KW - scRNA-seq KW - full-length transcriptome KW - immune cell population KW - teleost KW - infection Y1 - 2021 U6 - https://doi.org/10.3389/fimmu.2021.737332 SN - 1664-3224 VL - 12 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Manna, Vincenzo A1 - Zoccarato, Luca A1 - Banchi, Elisa A1 - Arnosti, Carol A1 - Grossart, Hans-Peter A1 - Celussi, Mauro T1 - Linking lifestyle and foraging strategies of marine bacteria BT - selfish behaviour of particle-attached bacteria in the northern Adriatic Sea JF - Environmental microbiology reports N2 - Microbe-mediated enzymatic hydrolysis of organic matter entails the production of hydrolysate, the recovery of which may be more or less efficient. The selfish uptake mechanism, recently discovered, allows microbes to hydrolyze polysaccharides and take up large oligomers, which are then degraded in the periplasmic space. By minimizing the hydrolysate loss, selfish behaviour may be profitable for free-living cells dwelling in a patchy substrate landscape. However, selfish uptake seems to be tailored to algal-derived polysaccharides, abundant in organic particles, suggesting that particle-attached microbes may use this strategy. We tracked selfish polysaccharides uptake in surface microbial communities of the northeastern Mediterranean Sea, linking the occurrence of this processing mode with microbial lifestyle. Additionally, we set up fluorescently labelled polysaccharides incubations supplying phytodetritus to investigate a 'pioneer' scenario for particle-attached microbes. Under both conditions, selfish behaviour was almost exclusively carried out by particle-attached microbes, suggesting that this mechanism may represent an advantage in the race for particle exploitation. Our findings shed light on the selfish potential of particle-attached microbes, suggesting multifaceted foraging strategies exerted by particle colonizers. Y1 - 2022 U6 - https://doi.org/10.1111/1758-2229.13059 SN - 1758-2229 VL - 14 IS - 4 SP - 549 EP - 558 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Zhang, Kai A1 - Hu, Jiege A1 - Yang, Shuai A1 - Xu, Wei A1 - Wang, Zhichao A1 - Zhuang, Peiwen A1 - Grossart, Hans-Peter A1 - Luo, Zhuhua T1 - Biodegradation of polyester polyurethane by the marine fungus Cladosporium halotolerans 6UPA1 JF - Journal of hazardous materials N2 - Lack of degradability and the accumulation of polymeric wastes increase the risk for the health of the environment. Recently, recycling of polymeric waste materials becomes increasingly important as raw materials for polymer synthesis are in short supply due to the rise in price and supply chain disruptions. As an important polymer, polyurethane (PU) is widely used in modern life, therefore, PU biodegradation is desirable to avoid its accumulation in the environment. In this study, we isolated a fungal strain Cladosporium halotolerans from the deep sea which can grow in mineral medium with a polyester PU (Impranil DLN) as a sole carbon source. Further, we demonstrate that it can degrade up to 80% of Impranil PU after 3 days of incubation at 28 celcius by breaking the carbonyl groups (1732 cm(-1)) and C-N-H bonds (1532 cm(-1) and 1247 cm(-1)) as confirmed by Fourier-transform infrared (FTIR) spectroscopy analysis. Gas chromatography-mass spectrometry (GC-MS) analysis revealed polyols and alkanes as PU degradation intermediates, indicating the hydrolysis of ester and urethane bonds. Esterase and urease activities were detected in 7 days-old cultures with PU as a carbon source. Transcriptome analysis showed a number of extracellular protein genes coding for enzymes such as cutinase, lipase, peroxidase and hydrophobic surface binding proteins A (HsbA) were expressed when cultivated on Impranil PU. The yeast two-hybrid assay revealed that the hydrophobic surface binding protein ChHsbA1 directly interacts with inducible esterases, ChLip1 (lipase) and ChCut1 (cutinase). Further, the KEGG pathway for "fatty acid degradation " was significantly enriched in Impranil PU inducible genes, indicating that the fungus may use the degradation intermediates to generate energy via this pathway. Taken together, our data indicates secretion of both esterase and hydrophobic surface binding proteins by C. halotolerans plays an important role in Impranil PU absorption and subsequent degradation. Our study provides a mechanistic insight into Impranil PU biodegradation by deep sea fungi and provides the basis for future development of biotechnological PU recycling. KW - Impranil PU degradation KW - Lipase KW - Cutinase KW - HsbA KW - Fatty acid degradation Y1 - 2022 U6 - https://doi.org/10.1016/j.jhazmat.2022.129406 SN - 0304-3894 SN - 1873-3336 VL - 437 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Perkins, Anita K. A1 - Santos, Isaac R. A1 - Rose, Andrew L. A1 - Schulz, Kai G. A1 - Grossart, Hans-Peter A1 - Eyre, Bradley D. A1 - Kelaher, Brendan P. A1 - Oakes, Joanne M. T1 - Production of dissolved carbon and alkalinity during macroalgal wrack degradation on beaches BT - a mesocosm experiment with implications for blue carbon JF - Biogeochemistry N2 - Marine macroalgae are a key primary producer in coastal ecosystems, but are often overlooked in blue carbon inventories. Large quantities of macroalgal detritus deposit on beaches, but the fate of wrack carbon (C) is little understood. If most of the wrack carbon is respired back to CO2, there would be no net carbon sequestration. However, if most of the wrack carbon is converted to bicarbonate (alkalinity) or refractory DOC, wrack deposition would represent net carbon sequestration if at least part of the metabolic products (e.g., reduced Fe and S) are permanently removed (i.e., long-term burial) and the DOC is not remineralised. To investigate the release of macroalgal C via porewater and its potential to contribute to C sequestration (blue carbon), we monitored the degradation of Ecklonia radiata in flow-through mesocosms simulating tidal flushing on sandy beaches. Over 60 days, 81% of added E. radiata organic matter (OM) decomposed. Per 1 mol of detritus C, the degradation produced 0.48 +/- 0.34 mol C of dissolved organic carbon (DOC) (59%) and 0.25 +/- 0.07 mol C of dissolved inorganic carbon (DIC) (31%) in porewater, and a small amount of CO2 (0.3 +/- 0.0 mol C; ca. 3%) which was emitted to the atmosphere. A significant amount of carbonate alkalinity was found in porewater, equating to 33% (0.27 +/- 0.05 mol C) of the total degraded C. The degradation occurred in two phases. In the first phase (days 0-3), 27% of the OM degraded, releasing highly reactive DOC. In the second phase (days 4-60), the labile DOC was converted to DIC. The mechanisms underlying E. radiata degradation were sulphate reduction and ammonification. It is likely that the carbonate alkalinity was primarily produced through sulphate reduction. The formation of carbonate alkalinity and semi-labile or refractory DOC from beach wrack has the potential to play an overlooked role in coastal carbon cycling and contribute to marine carbon sequestration. KW - Tidal pumping KW - Organic matter degradation KW - Carbon cycle KW - Mineralisation KW - Porewater exchange KW - Submarine groundwater discharge Y1 - 2022 U6 - https://doi.org/10.1007/s10533-022-00946-4 SN - 0168-2563 SN - 1573-515X VL - 160 IS - 2 SP - 159 EP - 175 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Hilt, Sabine A1 - Grossart, Hans-Peter A1 - McGinnis, Daniel F. A1 - Keppler, Frank T1 - Potential role of submerged macrophytes for oxic methane production in aquatic ecosystems JF - Limnology and oceanography N2 - Methane (CH4) from aquatic ecosystems contributes to about half of total global CH4 emissions to the atmosphere. Until recently, aquatic biogenic CH4 production was exclusively attributed to methanogenic archaea living under anoxic or suboxic conditions in sediments, bottom waters, and wetlands. However, evidence for oxic CH4 production (OMP) in freshwater, brackish, and marine habitats is increasing. Possible sources were found to be driven by various planktonic organisms supporting different OMP mechanisms. Surprisingly, submerged macrophytes have been fully ignored in studies on OMP, yet they are key components of littoral zones of ponds, lakes, and coastal systems. High CH4 concentrations in these zones have been attributed to organic substrate production promoting classic methanogenesis in the absence of oxygen. Here, we review existing studies and argue that, similar to terrestrial plants and phytoplankton, macroalgae and submerged macrophytes may directly or indirectly contribute to CH4 formation in oxic waters. We propose several potential direct and indirect mechanisms: (1) direct production of CH4; (2) production of CH4 precursors and facilitation of their bacterial breakdown or chemical conversion; (3) facilitation of classic methanogenesis; and (4) facilitation of CH4 ebullition. As submerged macrophytes occur in many freshwater and marine habitats, they are important in global carbon budgets and can strongly vary in their abundance due to seasonal and boom-bust dynamics. Knowledge on their contribution to OMP is therefore essential to gain a better understanding of spatial and temporal dynamics of CH4 emissions and thus to substantially reduce current uncertainties when estimating global CH4 emissions from aquatic ecosystems. Y1 - 2022 U6 - https://doi.org/10.1002/lno.12095 SN - 0024-3590 SN - 1939-5590 PB - Wiley CY - Hoboken ER - TY - GEN A1 - Schorn, Sina A1 - Salman-Carvalho, Verena A1 - Littmann, Sten A1 - Ionescu, Danny A1 - Grossart, Hans-Peter A1 - Cypionka, Heribert T1 - Cell architecture of the giant sulfur bacterium achromatium oxaliferum BT - Extra-cytoplasmic localization of calcium carbonate bodies T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Achromatium oxaliferum is a large sulfur bacterium easily recognized by large intracellular calcium carbonate bodies. Although these bodies often fill major parts of the cells' volume, their role and specific intracellular location are unclear. In this study, we used various microscopy and staining techniques to identify the cell compartment harboring the calcium carbonate bodies. We observed that Achromatium cells often lost their calcium carbonate bodies, either naturally or induced by treatments with diluted acids, ethanol, sodium bicarbonate and UV radiation which did not visibly affect the overall shape and motility of the cells (except for UV radiation). The water-soluble fluorescent dye fluorescein easily diffused into empty cavities remaining after calcium carbonate loss. Membranes (stained with Nile Red) formed a network stretching throughout the cell and surrounding empty or filled calcium carbonate cavities. The cytoplasm (stained with FITC and SYBR Green for nucleic acids) appeared highly condensed and showed spots of dissolved Ca2+ (stained with Fura-2). From our observations, we conclude that the calcium carbonate bodies are located in the periplasm, in extra-cytoplasmic pockets of the cytoplasmic membrane and are thus kept separate from the cell's cytoplasm. This periplasmic localization of the carbonate bodies might explain their dynamic formation and release upon environmental changes. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1356 KW - sulfur-bacteria KW - calcium carbonate inclusions KW - extra-cytoplasmic pockets KW - calcite Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-549935 SN - 1866-8372 IS - 2 ER - TY - JOUR A1 - Schorn, Sina A1 - Salman-Carvalho, Verena A1 - Littmann, Sten A1 - Ionescu, Danny A1 - Grossart, Hans-Peter A1 - Cypionka, Heribert T1 - Cell architecture of the giant sulfur bacterium achromatium oxaliferum BT - Extra-cytoplasmic localization of calcium carbonate bodies JF - FEMS Microbiology Ecology N2 - Achromatium oxaliferum is a large sulfur bacterium easily recognized by large intracellular calcium carbonate bodies. Although these bodies often fill major parts of the cells' volume, their role and specific intracellular location are unclear. In this study, we used various microscopy and staining techniques to identify the cell compartment harboring the calcium carbonate bodies. We observed that Achromatium cells often lost their calcium carbonate bodies, either naturally or induced by treatments with diluted acids, ethanol, sodium bicarbonate and UV radiation which did not visibly affect the overall shape and motility of the cells (except for UV radiation). The water-soluble fluorescent dye fluorescein easily diffused into empty cavities remaining after calcium carbonate loss. Membranes (stained with Nile Red) formed a network stretching throughout the cell and surrounding empty or filled calcium carbonate cavities. The cytoplasm (stained with FITC and SYBR Green for nucleic acids) appeared highly condensed and showed spots of dissolved Ca2+ (stained with Fura-2). From our observations, we conclude that the calcium carbonate bodies are located in the periplasm, in extra-cytoplasmic pockets of the cytoplasmic membrane and are thus kept separate from the cell's cytoplasm. This periplasmic localization of the carbonate bodies might explain their dynamic formation and release upon environmental changes. KW - sulfur-bacteria KW - calcium carbonate inclusions KW - extra-cytoplasmic pockets KW - calcite Y1 - 2019 U6 - https://doi.org/10.1093/femsec/fiz200 SN - 1574-6941 VL - 96 IS - 2 SP - 1 EP - 8 PB - Oxford University Press CY - Oxford ER - TY - GEN A1 - Masigol, Hossein A1 - Khodaparast, Seyed Akbar A1 - Mostowfizadeh-Ghalamfarsa, Reza A1 - Rojas-Jimenez, Keilor A1 - Woodhouse, Jason Nicholas A1 - Neubauer, Darshan A1 - Grossart, Hans-Peter T1 - Taxonomical and functional diversity of Saprolegniales in Anzali lagoon, Iran T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Studies on the diversity, distribution and ecological role of Saprolegniales (Oomycota) in freshwater ecosystems are currently receiving attention due to a greater understanding of their role in carbon cycling in various aquatic ecosystems. In this study, we characterized several Saprolegniales species isolated from Anzali lagoon, Gilan province, Iran, using morphological and molecular methods. Four species of Saprolegnia were identified, including S. anisospora and S. diclina as first reports for Iran, as well as Achlya strains, which were closely related to A. bisexualis, A. debaryana and A. intricata. Evaluation of the ligno-, cellulo- and chitinolytic activities was performed using plate assay methods. Most of the Saprolegniales isolates were obtained in autumn, and nearly 50% of the strains showed chitinolytic and cellulolytic activities. However, only a few Saprolegniales strains showed lignolytic activities. This study has important implications for better understanding the ecological niche of oomycetes, and to differentiate them from morphologically similar, but functionally different aquatic fungi in freshwater ecosystems. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1395 KW - Achlya KW - Saprolegnia KW - aquatic ecosystems KW - carbon cycling KW - polymer degradation KW - Saprolegniaceae KW - Achlyaceae Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515820 SN - 1866-8372 IS - 1 ER - TY - JOUR A1 - Masigol, Hossein A1 - Khodaparast, Seyed Akbar A1 - Mostowfizadeh-Ghalamfarsa, Reza A1 - Rojas-Jimenez, Keilor A1 - Woodhouse, Jason Nicholas A1 - Neubauer, Darshan A1 - Grossart, Hans-Peter T1 - Taxonomical and functional diversity of Saprolegniales in Anzali lagoon, Iran JF - Aquatic Ecology N2 - Studies on the diversity, distribution and ecological role of Saprolegniales (Oomycota) in freshwater ecosystems are currently receiving attention due to a greater understanding of their role in carbon cycling in various aquatic ecosystems. In this study, we characterized several Saprolegniales species isolated from Anzali lagoon, Gilan province, Iran, using morphological and molecular methods. Four species of Saprolegnia were identified, including S. anisospora and S. diclina as first reports for Iran, as well as Achlya strains, which were closely related to A. bisexualis, A. debaryana and A. intricata. Evaluation of the ligno-, cellulo- and chitinolytic activities was performed using plate assay methods. Most of the Saprolegniales isolates were obtained in autumn, and nearly 50% of the strains showed chitinolytic and cellulolytic activities. However, only a few Saprolegniales strains showed lignolytic activities. This study has important implications for better understanding the ecological niche of oomycetes, and to differentiate them from morphologically similar, but functionally different aquatic fungi in freshwater ecosystems. KW - Achlya KW - Saprolegnia KW - aquatic ecosystems KW - carbon cycling KW - polymer degradation KW - Saprolegniaceae KW - Achlyaceae Y1 - 2020 U6 - https://doi.org/10.1007/s10452-019-09745-w SN - 1573-5125 SN - 1386-2588 VL - 54 IS - 1 SP - 323 EP - 336 PB - Springer Science CY - Dordrecht ER - TY - JOUR A1 - Aichner, Bernhard A1 - Dubbert, David A1 - Kiel, Christine A1 - Kohnert, Katrin A1 - Ogashawara, Igor A1 - Jechow, Andreas A1 - Harpenslager, Sarah-Faye A1 - Hölker, Franz A1 - Nejstgaard, Jens Christian A1 - Grossart, Hans-Peter A1 - Singer, Gabriel A1 - Wollrab, Sabine A1 - Berger, Stella Angela T1 - Spatial and seasonal patterns of water isotopes in northeastern German lakes JF - Earth system science data : ESSD N2 - Water stable isotopes (delta O-18 and delta H-2) were analyzed in samples collected in lakes, associated with riverine systems in northeastern Germany, throughout 2020. The dataset (Aichner et al., 2021; https://doi.org/10.1594/PANGAEA.935633) is derived from water samples collected at (a) lake shores (sampled in March and July 2020), (b) buoys which were temporarily installed in deep parts of the lake (sampled monthly from March to October 2020), (c) multiple spatially distributed spots in four selected lakes (in September 2020), and (d) the outflow of Muggelsee (sampled biweekly from March 2020 to January 2021). At shores, water was sampled with a pipette from 40-60 cm below the water surface and directly transferred into a measurement vial, while at buoys a Limnos water sampler was used to obtain samples from 1 m below the surface. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer, with a measurement uncertainty of < 0.15 parts per thousand (delta O-18) and < 0.0 parts per thousand (delta H-2). The data give information about the vegetation period and the full seasonal isotope amplitude in the sampled lakes and about spatial isotope variability in different branches of the associated riverine systems. Y1 - 2022 U6 - https://doi.org/10.5194/essd-14-1857-2022 SN - 1866-3508 SN - 1866-3516 VL - 14 IS - 4 SP - 1857 EP - 1867 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Schellenberg, Johannes A1 - Reichert, Jessica A1 - Hardt, Martin A1 - Klingelhöfer, Ines A1 - Morlock, Gertrud A1 - Schubert, Patrick A1 - Bižić, Mina A1 - Grossart, Hans-Peter A1 - Kämpfer, Peter A1 - Wilke, Thomas A1 - Glaeser, Stefanie P. T1 - The bacterial microbiome of the long-term aquarium cultured high-microbial abundance sponge Haliclona cnidata BT - sustained bioactivity despite community shifts under detrimental conditions JF - Frontiers in Marine Science N2 - Marine sponges host highly diverse but specific bacterial communities that provide essential functions for the sponge holobiont, including antimicrobial defense. Here, we characterized the bacterial microbiome of the marine sponge Haliclona cnidata that has been in culture in an artificial marine aquarium system. We tested the hypotheses (1) that the long-term aquarium cultured sponge H. cnidata is tightly associated with a typical sponge bacterial microbiota and (2) that the symbiotic Bacteria sustain bioactivity under harmful environmental conditions to facilitate holobiont survival by preventing pathogen invasion. Microscopic and phylogenetic analyses of the bacterial microbiota revealed that H. cnidata represents a high microbial abundance (HMA) sponge with a temporally stable bacterial community that significantly shifts with changing aquarium conditions. A 4-week incubation experiment was performed in small closed aquarium systems with antibiotic and/or light exclusion treatments to reduce the total bacterial and photosynthetically active sponge-associated microbiota to a treatment-specific resilient community. While the holobiont was severely affected by the experimental treatment (i.e., bleaching of the sponge, reduced bacterial abundance, shifted bacterial community composition), the biological defense and bacterial community interactions (i.e., quorum sensing activity) remained intact. 16S rRNA gene amplicon sequencing revealed a resilient community of 105 bacterial taxa, which remained in the treated sponges. These 105 taxa accounted for a relative abundance of 72-83% of the bacterial sponge microbiota of non-treated sponge fragments that have been cultured under the same conditions. We conclude that a sponge-specific resilient community stays biologically active under harmful environmental conditions, facilitating the resilience of the holobiont. In H. cnidata, bacteria are located in bacteriocytes, which may have contributed to the observed phenomenon. KW - HMA sponge KW - bacterial symbionts KW - holobiont KW - antimicrobial defense KW - quorum sensing KW - bacteriocytes Y1 - 2020 U6 - https://doi.org/10.3389/fmars.2020.00266 SN - 2296-7745 VL - 7 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Xiao, Shangbin A1 - Liu, Liu A1 - Wang, Wei A1 - Lorke, Andreas A1 - Woodhouse, Jason Nicholas A1 - Grossart, Hans-Peter T1 - A Fast-Response Automated Gas Equilibrator (FaRAGE) for continuous in situ measurement of CH4 and CO2 dissolved in water JF - Hydrology and earth system sciences : HESS N2 - Biogenic greenhouse gas emissions, e.g., of methane (CH4) and carbon dioxide (CO2) from inland waters, contribute substantially to global warming. In aquatic systems, dissolved greenhouse gases are highly heterogeneous in both space and time. To better understand the biological and physical processes that affect sources and sinks of both CH4 and CO2, their dissolved concentrations need to be measured with high spatial and temporal resolution. To achieve this goal, we developed the Fast-Response Automated Gas Equilibrator (FaRAGE) for real-time in situ measurement of dissolved CH4 and CO2 concentrations at the water surface and in the water column. FaRAGE can achieve an exceptionally short response time (t(95%) = 12 s when including the response time of the gas analyzer) while retaining an equilibration ratio of 62.6% and a measurement accuracy of 0.5% for CH4. A similar performance was observed for dissolved CO2 (t(95%) = 10 s, equilibration ratio 67.1 %). An equilibration ratio as high as 91.8% can be reached at the cost of a slightly increased response time (16 s). The FaRAGE is capable of continuously measuring dissolved CO2 and CH4 concentrations in the nM-to-submM (10(-9)-10(-3) mol L-1) range with a detection limit of subnM (10(-10) mol L-1), when coupling with a cavity ring-down greenhouse gas analyzer (Picarro GasScouter). FaRAGE allows for the possibility of mapping dissolved concentration in a "quasi" three-dimensional manner in lakes and provides an inexpensive alternative to other commercial gas equilibrators. It is simple to operate and suitable for continuous monitoring with a strong tolerance for suspended particles. While the FaRAGE is developed for inland waters, it can be also applied to ocean waters by tuning the gas-water mixing ratio. The FaRAGE is easily adapted to suit other gas analyzers expanding the range of potential applications, including nitrous oxide and isotopic composition of the gases. Y1 - 2020 U6 - https://doi.org/10.5194/hess-24-3871-2020 SN - 1027-5606 SN - 1607-7938 VL - 24 IS - 7 SP - 3871 EP - 3880 PB - European Geosciences Union (EGU) ; Copernicus CY - Munich ER - TY - JOUR A1 - Villalba, Luis Alberto A1 - Karnatak, Rajat A1 - Grossart, Hans-Peter A1 - Wollrab, Sabine T1 - Flexible habitat choice of pelagic bacteria increases system stability and energy flow through the microbial loop JF - Limnology and oceanography : L & O N2 - Pelagic bacteria can be classified into free-living and particle-attached life modes, which either dwell in the water column or attach to suspended particles. Bacteria with a generalist life style, however, can actively shift between these two habitats. Globally increasing densities of natural and artificial particles enhance habitat heterogeneity, with potential consequences for system stability and trophic transfer through aquatic food webs. To better decipher the dynamics of microbial communities, we investigated the influence of adaptive vs. fixed habitat choice on species coexistence for a simplified bacterial community by analyzing a corresponding food web model, consisting of two specialist bacterial prey species (free and attached), a generalist bacterial prey species with the ability to shift between both habitats, and two protist predators, specialized on either water or particle compartment. For simplicity we assume a shared resource pool, considering particles only for colonization but not as a source for nutrients or carbon, that is, inert particles like microplastics or inorganic sediments. The model predicts coexistence on a cyclic attractor between fixed and flexible bacteria, if the costs for adaptive habitat choice can be balanced by adaptation speed. The presence of adaptive prey dampens predator-prey cycle amplitudes, contributing to system stabilization resulting in higher mean predator biomass compared to specialist prey only. Thus, in pelagic microbial systems, flexible habitat choice at the prey level has important implications for system stability and magnitude of energy flow through the microbial loop. Y1 - 2022 U6 - https://doi.org/10.1002/lno.12091 SN - 0024-3590 SN - 1939-5590 VL - 67 IS - 6 SP - 1402 EP - 1415 PB - Wiley-Blackwell CY - Oxford [u.a.] ER - TY - JOUR A1 - Ilicic, Doris A1 - Grossart, Hans-Peter T1 - Basal parasitic fungi in marine food webs-a mystery yet to unravel JF - Journal of Fungi N2 - Although aquatic and parasitic fungi have been well known for more than 100 years, they have only recently received increased awareness due to their key roles in microbial food webs and biogeochemical cycles. There is growing evidence indicating that fungi inhabit a wide range of marine habitats, from the deep sea all the way to surface waters, and recent advances in molecular tools, in particular metagenome approaches, reveal that their diversity is much greater and their ecological roles more important than previously considered. Parasitism constitutes one of the most widespread ecological interactions in nature, occurring in almost all environments. Despite that, the diversity of fungal parasites, their ecological functions, and, in particular their interactions with other microorganisms remain largely speculative, unexplored and are often missing from current theoretical concepts in marine ecology and biogeochemistry. In this review, we summarize and discuss recent research avenues on parasitic fungi and their ecological potential in marine ecosystems, e.g., the fungal shunt, and emphasize the need for further research. KW - basal fungi KW - parasites KW - Chytridiomycota KW - Rozellomycota KW - food web KW - biological carbon pump Y1 - 2022 U6 - https://doi.org/10.3390/jof8020114 SN - 2309-608X VL - 8 IS - 2 PB - MDPI CY - Basel ER - TY - GEN A1 - Ilicic, Doris A1 - Woodhouse, Jason A1 - Karsten, Ulf A1 - Zimmermann, Jonas A1 - Wichard, Thomas A1 - Quartino, Maria Liliana A1 - Campana, Gabriela Laura A1 - Livenets, Alexandra A1 - Van den Wyngaert, Silke A1 - Grossart, Hans-Peter T1 - Antarctic Glacial Meltwater Impacts the Diversity of Fungal Parasites Associated With Benthic Diatoms in Shallow Coastal Zones T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Aquatic ecosystems are frequently overlooked as fungal habitats, although there is increasing evidence that their diversity and ecological importance are greater than previously considered. Aquatic fungi are critical and abundant components of nutrient cycling and food web dynamics, e.g., exerting top-down control on phytoplankton communities and forming symbioses with many marine microorganisms. However, their relevance for microphytobenthic communities is almost unexplored. In the light of global warming, polar regions face extreme changes in abiotic factors with a severe impact on biodiversity and ecosystem functioning. Therefore, this study aimed to describe, for the first time, fungal diversity in Antarctic benthic habitats along the salinity gradient and to determine the co-occurrence of fungal parasites with their algal hosts, which were dominated by benthic diatoms. Our results reveal that Ascomycota and Chytridiomycota are the most abundant fungal taxa in these habitats. We show that also in Antarctic waters, salinity has a major impact on shaping not just fungal but rather the whole eukaryotic community composition, with a diversity of aquatic fungi increasing as salinity decreases. Moreover, we determined correlations between putative fungal parasites and potential benthic diatom hosts, highlighting the need for further systematic analysis of fungal diversity along with studies on taxonomy and ecological roles of Chytridiomycota. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1290 KW - Antarctica KW - aquatic fungi KW - Chytridiomycota KW - phytoplankton host KW - salinity gradient KW - Illumina amplicon sequencing KW - Carlini Station Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-572895 SN - 1866-8372 IS - 1290 ER - TY - JOUR A1 - Ilicic, Doris A1 - Woodhouse, Jason A1 - Karsten, Ulf A1 - Zimmermann, Jonas A1 - Wichard, Thomas A1 - Quartino, Maria Liliana A1 - Campana, Gabriela Laura A1 - Livenets, Alexandra A1 - Van den Wyngaert, Silke A1 - Grossart, Hans-Peter T1 - Antarctic Glacial Meltwater Impacts the Diversity of Fungal Parasites Associated With Benthic Diatoms in Shallow Coastal Zones JF - Frontiers in microbiology N2 - Aquatic ecosystems are frequently overlooked as fungal habitats, although there is increasing evidence that their diversity and ecological importance are greater than previously considered. Aquatic fungi are critical and abundant components of nutrient cycling and food web dynamics, e.g., exerting top-down control on phytoplankton communities and forming symbioses with many marine microorganisms. However, their relevance for microphytobenthic communities is almost unexplored. In the light of global warming, polar regions face extreme changes in abiotic factors with a severe impact on biodiversity and ecosystem functioning. Therefore, this study aimed to describe, for the first time, fungal diversity in Antarctic benthic habitats along the salinity gradient and to determine the co-occurrence of fungal parasites with their algal hosts, which were dominated by benthic diatoms. Our results reveal that Ascomycota and Chytridiomycota are the most abundant fungal taxa in these habitats. We show that also in Antarctic waters, salinity has a major impact on shaping not just fungal but rather the whole eukaryotic community composition, with a diversity of aquatic fungi increasing as salinity decreases. Moreover, we determined correlations between putative fungal parasites and potential benthic diatom hosts, highlighting the need for further systematic analysis of fungal diversity along with studies on taxonomy and ecological roles of Chytridiomycota. KW - Antarctica KW - aquatic fungi KW - Chytridiomycota KW - phytoplankton host KW - salinity gradient KW - Illumina amplicon sequencing KW - Carlini Station Y1 - 2022 U6 - https://doi.org/10.3389/fmicb.2022.805694 SN - 1664-302X IS - 13 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - van Rees, Charles B. A1 - Waylen, Kerry A. A1 - Schmidt-Kloiber, Astrid A1 - Thackeray, Stephen J. A1 - Kalinkat, Gregor A1 - Martens, Koen A1 - Domisch, Sami A1 - Lillebo, Ana A1 - Hermoso, Virgilio A1 - Grossart, Hans-Peter A1 - Schinegger, Rafaela A1 - Decleer, Kris A1 - Adriaens, Tim A1 - Denys, Luc A1 - Jaric, Ivan A1 - Janse, Jan H. A1 - Monaghan, Michael T. A1 - De Wever, Aaike A1 - Geijzendorffer, Ilse A1 - Adamescu, Mihai C. A1 - Jähnig, Sonja C. T1 - Safeguarding freshwater life beyond 2020 BT - recommendations for the new global biodiversity framework from the European experience JF - Conservation letters N2 - Plans are currently being drafted for the next decade of action on biodiversity-both the post-2020 Global Biodiversity Framework of the Convention on Biological Diversity (CBD) and Biodiversity Strategy of the European Union (EU). Freshwater biodiversity is disproportionately threatened and underprioritized relative to the marine and terrestrial biota, despite supporting a richness of species and ecosystems with their own intrinsic value and providing multiple essential ecosystem services. Future policies and strategies must have a greater focus on the unique ecology of freshwater life and its multiple threats, and now is a critical time to reflect on how this may be achieved. We identify priority topics including environmental flows, water quality, invasive species, integrated water resources management, strategic conservation planning, and emerging technologies for freshwater ecosystem monitoring. We synthesize these topics with decades of first-hand experience and recent literature into 14 special recommendations for global freshwater biodiversity conservation based on the successes and setbacks of European policy, management, and research. Applying and following these recommendations will inform and enhance the ability of global and European post-2020 biodiversity agreements to halt and reverse the rapid global decline of freshwater biodiversity. KW - climate change KW - conservation KW - ecosystem services KW - rivers KW - sustainable KW - development goals KW - water resources KW - wetlands Y1 - 2020 U6 - https://doi.org/10.1111/conl.12771 SN - 1755-263X VL - 14 IS - 1 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Hoke, Alexa A1 - Woodhouse, Jason Nicholas A1 - Zoccarato, Luca A1 - McCarthy, Valerie A1 - de Eyto, Elvira A1 - Caldero-Pascual, Maria A1 - Geffroy, Ewan A1 - Dillane, Mary A1 - Grossart, Hans-Peter A1 - Jennings, Eleanor T1 - Impacts of extreme weather events on bacterial community composition of a temperate humic lake JF - Water N2 - Extreme weather events are projected to increase in frequency and intensity as climate change continues. Heterotrophic bacteria play a critical role in lake ecosystems, yet little research has been done to determine how they are affected by such extremes. The purpose of this study was to use high-throughput sequencing to explore the bacterial community composition of a humic oligotrophic lake on the North Atlantic Irish coast and to assess the impacts on composition dynamics related to extreme weather events. Samples for sequencing were collected from Lough Feeagh on a fortnightly basis from April to November 2018. Filtration was used to separate free-living and particle-associated bacterial communities and amplicon sequencing was performed for the 16S rRNA V4 region. Two named storms, six high discharge events, and one drought period occurred during the sampling period. These events had variable, context-dependent effects on bacterial communities in Lough Feeagh. The particle-associated community was found to be more likely to respond to physical changes, such as mixing, while the free-living population responded to changes in nutrient and carbon concentrations. Generally, however, the high stability of the bacterial community observed in Lough Feeagh suggests that the bacterial community is relatively resilient to extreme weather events. KW - extreme weather event KW - storm KW - drought KW - bacteria KW - free-living KW - particle-associated KW - humic lake Y1 - 2020 U6 - https://doi.org/10.3390/w12102757 SN - 2073-4441 VL - 12 IS - 10 PB - MDPI CY - Basel ER - TY - JOUR A1 - Hornick, Thomas A1 - Bach, Lennart T. A1 - Crawfurd, Katharine J. A1 - Spilling, Kristian A1 - Achterberg, Eric P. A1 - Woodhouse, Jason Nicholas A1 - Schulz, Kai G. A1 - Brussaard, Corina P. D. A1 - Riebesell, Ulf A1 - Grossart, Hans-Peter T1 - Ocean acidification impacts bacteria-phytoplankton coupling at low-nutrient conditions JF - Biogeosciences N2 - The oceans absorb about a quarter of the annually produced anthropogenic atmospheric carbon dioxide (CO2), resulting in a decrease in surface water pH, a process termed ocean acidification (OA). Surprisingly little is known about how OA affects the physiology of heterotrophic bacteria or the coupling of heterotrophic bacteria to phytoplankton when nutrients are limited. Previous experiments were, for the most part, undertaken during productive phases or following nutrient additions designed to stimulate algal blooms. Therefore, we performed an in situ large-volume mesocosm (similar to 55 m(3)) experiment in the Baltic Sea by simulating different fugacities of CO2 (fCO(2)) extending from present to future conditions. The study was conducted in July-August after the nominal spring bloom, in order to maintain low-nutrient conditions throughout the experiment. This resulted in phytoplankton communities dominated by small-sized functional groups (picophytoplankton). There was no consistent fCO(2)-induced effect on bacterial protein production (BPP), cell-specific BPP (csBPP) or biovolumes (BVs) of either free-living (FL) or particle-associated (PA) heterotrophic bacteria, when considered as individual components (univariate analyses). Permutational Multivariate Analysis of Variance (PERMANOVA) revealed a significant effect of the fCO(2) treatment on entire assemblages of dissolved and particulate nutrients, metabolic parameters and the bacteria-phytoplankton community. However, distance-based linear modelling only identified fCO(2) as a factor explaining the variability observed amongst the microbial community composition, but not for explaining variability within the metabolic parameters. This suggests that fCO(2) impacts on microbial metabolic parameters occurred indirectly through varying physicochemical parameters and microbial species composition. Cluster analyses examining the co-occurrence of different functional groups of bacteria and phytoplankton further revealed a separation of the four fCO(2)-treated mesocosms from both control mesocosms, indicating that complex trophic interactions might be altered in a future acidified ocean. Possible consequences for nutrient cycling and carbon export are still largely unknown, in particular in a nutrient-limited ocean. Y1 - 2017 U6 - https://doi.org/10.5194/bg-14-1-2017 SN - 1726-4170 SN - 1726-4189 VL - 14 IS - 1 SP - 1 EP - 15 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Ferrera, Isabel A1 - Sarmento, Hugo A1 - Priscu, John C. A1 - Chiuchiolo, Amy A1 - Gonzalez, Jose M. A1 - Grossart, Hans-Peter T1 - Diversity and Distribution of Freshwater Aerobic Anoxygenic Phototrophic Bacteria across a Wide Latitudinal Gradient JF - Frontiers in microbiology N2 - Aerobic anoxygenic phototrophs (AAPs) have been shown to exist in numerous marine and brackish environments where they are hypothesized to play important ecological roles. Despite their potential significance, the study of freshwater AAPs is in its infancy and limited to local investigations. Here, we explore the occurrence, diversity and distribution of AAPs in lakes covering a wide latitudinal gradient: Mongolian and German lakes located in temperate regions of Eurasia, tropical Great East African lakes, and polar permanently ice-covered Antarctic lakes. Our results show a widespread distribution of AAPs in lakes with contrasting environmental conditions and confirm that this group is composed of different members of the Alpha- and Betaproteobacteria. While latitude does not seem to strongly influence AAP abundance, clear patterns of community structure and composition along geographic regions were observed as indicated by a strong macro-geographical signal in the taxonomical composition of AAPs. Overall, our results suggest that the distribution patterns of freshwater AAPs are likely driven by a combination of small-scale environmental conditions (specific of each lake and region) and large-scale geographic factors (climatic regions across a latitudinal gradient). KW - AAP bacteria KW - photoheterotrophy KW - pufM gene KW - freshwater lakes KW - latitudinal gradients KW - biogeography Y1 - 2017 U6 - https://doi.org/10.3389/fmicb.2017.00175 SN - 1664-302X VL - 8 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Weyhenmeyer, Gesa A. A1 - Mackay, Murray A1 - Stockwell, Jason D. A1 - Thiery, Wim A1 - Grossart, Hans-Peter A1 - Augusto-Silva, Petala B. A1 - Baulch, Helen M. A1 - de Eyto, Elvira A1 - Hejzlar, Josef A1 - Kangur, Kuelli A1 - Kirillin, Georgiy A1 - Pierson, Don C. A1 - Rusak, James A. A1 - Sadro, Steven A1 - Woolway, R. Iestyn T1 - Citizen science shows systematic changes in the temperature difference between air and inland waters with global warming JF - Scientific reports N2 - Citizen science projects have a long history in ecological studies. The research usefulness of such projects is dependent on applying simple and standardized methods. Here, we conducted a citizen science project that involved more than 3500 Swedish high school students to examine the temperature difference between surface water and the overlying air (T-w-T-a) as a proxy for sensible heat flux (Q(H)). If Q(H) is directed upward, corresponding to positive T-w-T-a, it can enhance CO2 and CH4 emissions from inland waters, thereby contributing to increased greenhouse gas concentrations in the atmosphere. The students found mostly negative T-w-T-a across small ponds, lakes, streams/rivers and the sea shore (i.e. downward Q(H)), with T-w-T-a becoming increasingly negative with increasing T-a. Further examination of T-w-T-a using high-frequency temperature data from inland waters across the globe confirmed that T-w-T-a is linearly related to T-a. Using the longest available high-frequency temperature time series from Lake Erken, Sweden, we found a rapid increase in the occasions of negative T-w-T-a with increasing annual mean T-a since 1989. From these results, we can expect that ongoing and projected global warming will result in increasingly negative T-w-T-a, thereby reducing CO2 and CH4 transfer velocities from inland waters into the atmosphere. Y1 - 2017 U6 - https://doi.org/10.1038/srep43890 SN - 2045-2322 VL - 7 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - McGinnis, Daniel F. A1 - Flury, Sabine A1 - Tang, Kam W. A1 - Grossart, Hans-Peter T1 - Porewater methane transport within the gas vesicles of diurnally migrating Chaoborus spp. BT - an energetic advantage JF - Scientific reports N2 - Diurnally-migrating Chaoborus spp. reach populations of up to 130,000 individuals m−2 in lakes up to 70 meters deep on all continents except Antarctica. Linked to eutrophication, migrating Chaoborus spp. dwell in the anoxic sediment during daytime and feed in the oxic surface layer at night. Our experiments show that by burrowing into the sediment, Chaoborus spp. utilize the high dissolved gas partial pressure of sediment methane to inflate their tracheal sacs. This mechanism provides a significant energetic advantage that allows the larvae to migrate via passive buoyancy rather than more energy-costly swimming. The Chaoborus spp. larvae, in addition to potentially releasing sediment methane bubbles twice a day by entering and leaving the sediment, also transport porewater methane within their gas vesicles into the water column, resulting in a flux of 0.01–2 mol m−2 yr−1 depending on population density and water depth. Chaoborus spp. emerging annually as flies also result in 0.1–6 mol m−2 yr−1 of carbon export from the system. Finding the tipping point in lake eutrophication enabling this methane-powered migration mechanism is crucial for ultimately reconstructing the geographical expansion of Chaoborus spp., and the corresponding shifts in the lake’s biogeochemistry, carbon cycling and food web structure. Y1 - 2017 U6 - https://doi.org/10.1038/srep44478 SN - 2045-2322 VL - 7 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Wurzbacher, Christian A1 - Fuchs, Andrea A1 - Attermeyer, Katrin A1 - Frindte, Katharina A1 - Grossart, Hans-Peter A1 - Hupfer, Michael A1 - Casper, Peter A1 - Monaghan, Michael T. T1 - Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment JF - Microbiome N2 - Background: Lake sediments harbor diverse microbial communities that cycle carbon and nutrients while being constantly colonized and potentially buried by organic matter sinking from the water column. The interaction of activity and burial remained largely unexplored in aquatic sediments. We aimed to relate taxonomic composition to sediment biogeochemical parameters, test whether community turnover with depth resulted from taxonomic replacement or from richness effects, and to provide a basic model for the vertical community structure in sediments. Methods: We analyzed four replicate sediment cores taken from 30-m depth in oligo-mesotrophic Lake Stechlin in northern Germany. Each 30-cm core spanned ca. 170 years of sediment accumulation according to Cs-137 dating and was sectioned into layers 1-4 cm thick. We examined a full suite of biogeochemical parameters and used DNA metabarcoding to examine community composition of microbial Archaea, Bacteria, and Eukaryota. Results: Community beta-diversity indicated nearly complete turnover within the uppermost 30 cm. We observed a pronounced shift from Eukaryota- and Bacteria-dominated upper layers (<5 cm) to Bacteria-dominated intermediate layers (5-14 cm) and to deep layers (>14 cm) dominated by enigmatic Archaea that typically occur in deep-sea sediments. Taxonomic replacement was the prevalent mechanism in structuring the community composition and was linked to parameters indicative of microbial activity (e.g., CO2 and CH4 concentration, bacterial protein production). Richness loss played a lesser role but was linked to conservative parameters (e.g., C, N, P) indicative of past conditions. Conclusions: By including all three domains, we were able to directly link the exponential decay of eukaryotes with the active sediment microbial community. The dominance of Archaea in deeper layers confirms earlier findings from marine systems and establishes freshwater sediments as a potential low-energy environment, similar to deep sea sediments. We propose a general model of sediment structure and function based on microbial characteristics and burial processes. An upper "replacement horizon" is dominated by rapid taxonomic turnover with depth, high microbial activity, and biotic interactions. A lower "depauperate horizon" is characterized by low taxonomic richness, more stable "low-energy" conditions, and a dominance of enigmatic Archaea. KW - Archaea KW - Eukaryota KW - Bacteria KW - Community KW - Freshwater KW - Lake KW - DNA metabarcoding KW - Beta-diversity KW - Sediment KW - Turnover Y1 - 2017 U6 - https://doi.org/10.1186/s40168-017-0255-9 SN - 2049-2618 VL - 5 PB - BioMed Central CY - London ER - TY - JOUR A1 - Perkins, Anita A1 - Rose, Andrew A1 - Grossart, Hans-Peter A1 - Rojas-Jimenez, Keilor Osvaldo A1 - Barroso Prescott, Selva Kiri A1 - Oakes, Joanne M. T1 - Oxic and Anoxic Organic Polymer Degradation Potential of Endophytic Fungi From the Marine Macroalga, Ecklonia radiata JF - Frontiers in Microbiology N2 - Cellulose and chitin are the most abundant polymeric, organic carbon source globally. Thus, microbes degrading these polymers significantly influence global carbon cycling and greenhouse gas production. Fungi are recognized as important for cellulose decomposition in terrestrial environments, but are far less studied in marine environments, where bacterial organic matter degradation pathways tend to receive more attention. In this study, we investigated the potential of fungi to degrade kelp detritus, which is a major source of cellulose in marine systems. Given that kelp detritus can be transported considerable distances in the marine environment, we were specifically interested in the capability of endophytic fungi, which are transported with detritus, to ultimately contribute to kelp detritus degradation. We isolated 10 species and two strains of endophytic fungi from the kelp Ecklonia radiata. We then used a dye decolorization assay to assess their ability to degrade organic polymers (lignin, cellulose, and hemicellulose) under both oxic and anoxic conditions and compared their degradation ability with common terrestrial fungi. Under oxic conditions, there was evidence that Ascomycota isolates produced cellulose-degrading extracellular enzymes (associated with manganese peroxidase and sulfur-containing lignin peroxidase), while Mucoromycota isolates appeared to produce both lignin and cellulose-degrading extracellular enzymes, and all Basidiomycota isolates produced lignin-degrading enzymes (associated with laccase and lignin peroxidase). Under anoxic conditions, only three kelp endophytes degraded cellulose. We concluded that kelp fungal endophytes can contribute to cellulose degradation in both oxic and anoxic environments. Thus, endophytic kelp fungi may play a significant role in marine carbon cycling via polymeric organic matter degradation. KW - kelp KW - fungi KW - endophytes KW - carbon cycling KW - extracellular enzymes KW - cellulose polymeric organic matter Y1 - 2021 U6 - https://doi.org/10.3389/fmicb.2021.726138 SN - 1664-302X VL - 12 SP - 1 EP - 13 PB - Frontiers in microbiology CY - Lausanne, Schweiz ER - TY - GEN A1 - Perkins, Anita A1 - Rose, Andrew A1 - Grossart, Hans-Peter A1 - Rojas-Jimenez, Keilor Osvaldo A1 - Barroso Prescott, Selva Kiri A1 - Oakes, Joanne M. T1 - Oxic and Anoxic Organic Polymer Degradation Potential of Endophytic Fungi From the Marine Macroalga, Ecklonia radiata T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Cellulose and chitin are the most abundant polymeric, organic carbon source globally. Thus, microbes degrading these polymers significantly influence global carbon cycling and greenhouse gas production. Fungi are recognized as important for cellulose decomposition in terrestrial environments, but are far less studied in marine environments, where bacterial organic matter degradation pathways tend to receive more attention. In this study, we investigated the potential of fungi to degrade kelp detritus, which is a major source of cellulose in marine systems. Given that kelp detritus can be transported considerable distances in the marine environment, we were specifically interested in the capability of endophytic fungi, which are transported with detritus, to ultimately contribute to kelp detritus degradation. We isolated 10 species and two strains of endophytic fungi from the kelp Ecklonia radiata. We then used a dye decolorization assay to assess their ability to degrade organic polymers (lignin, cellulose, and hemicellulose) under both oxic and anoxic conditions and compared their degradation ability with common terrestrial fungi. Under oxic conditions, there was evidence that Ascomycota isolates produced cellulose-degrading extracellular enzymes (associated with manganese peroxidase and sulfur-containing lignin peroxidase), while Mucoromycota isolates appeared to produce both lignin and cellulose-degrading extracellular enzymes, and all Basidiomycota isolates produced lignin-degrading enzymes (associated with laccase and lignin peroxidase). Under anoxic conditions, only three kelp endophytes degraded cellulose. We concluded that kelp fungal endophytes can contribute to cellulose degradation in both oxic and anoxic environments. Thus, endophytic kelp fungi may play a significant role in marine carbon cycling via polymeric organic matter degradation. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1246 KW - kelp KW - fungi KW - endophytes KW - carbon cycling KW - extracellular enzymes KW - cellulose polymeric organic matter Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-550520 SN - 1866-8372 VL - 12 SP - 1 EP - 13 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Van den Wyngaert, Silke A1 - Seto, Kensuke A1 - Rojas-Jimenez, Keilor A1 - Kagami, Maiko A1 - Grossart, Hans-Peter T1 - A New Parasitic Chytrid, Staurastromyces oculus (Rhizophydiales, Staurastromy-cetaceae fam. nov.), Infecting the Freshwater Desmid Staurastrum sp. JF - Protist N2 - Chytrids are a diverse group of ubiquitous true zoosporic fungi. The recent molecular discovery of a large diversity of undescribed chytrids has raised awareness on their important, but so far understudied ecological role in aquatic ecosystems. In the pelagic zone, of both freshwater and marine ecosystems, many chytrid species have been morphologically described as parasites on almost all major groups of phytoplankton. However, the majority of these parasitic chytrids has rarely been isolated and lack DNA sequence data, resulting in a large proportion of "dark taxa" in databases. Here, we report on the isolation and in-depth morphological, molecular and host range characterization of a chytrid infecting the common freshwater desmid Staurastrum sp. We provide first insights on the metabolic activity of the different chytrid development stages by using the vital dye FUN (R)-1 (2-chloro-4-[2,3-dihydro-3-methyl-[benzo-1,3-thiazol-2-yl]-methylidene]-1-phenylquinolinium iodide). Cross infection experiments suggest that this chytrid is an obligate parasite and specific for the genus Staurastrum sp. Phylogenetic analysis, based on ITS1-5.8S-ITS2 and 28S rDNA sequences, placed it in the order Rhizophydiales. Based on the unique zoospore ultrastructure, combined with thallus morphology, and molecular phylogenetic placement, we describe this parasitic chytrid as a new genus and species Staurastromyces oculus, within a new family Staurastromycetaceae. (C) 2017 Elsevier GmbH. All rights reserved. KW - Chytrids KW - parasite KW - phytoplankton KW - Staurastromyces oculus KW - Staurastrum sp. Y1 - 2017 U6 - https://doi.org/10.1016/j.protis.2017.05.001 SN - 1434-4610 VL - 168 SP - 392 EP - 407 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Rojas-Jimenez, Keilor A1 - Fonvielle, Jeremy Andre A1 - Ma, Hua A1 - Grossart, Hans-Peter T1 - Transformation of humic substances by the freshwater Ascomycete Cladosporium sp. JF - Waterbird N2 - The ecological relevance of fungi in freshwater ecosystems is becoming increasingly evident, particularly in processing the extensive amounts of polymeric organic carbon such as cellulose, chitin, and humic substances (HS). We isolated several fungal strains from oligo-mesotrophic Lake Stechlin, Brandenburg, Germany, and analyzed their ability to degrade polymeric-like substrates. Using liquid chromatography-organic carbon detection, we determined the byproducts of HS transformation by the freshwater fungus Cladosporium sp. KR14. We demonstrate the ability of this fungus to degrade and simultaneously synthesize HS, and that transformation processes were intensified when iron, as indicator of the occurrence of Fenton reactions, was present in the medium. Furthermore, we showed that structural complexity of the HS produced changed with the availability of other polymeric substances in the medium. Our study highlights the contribution of freshwater Ascomycetes to the transformation of complex organic compounds. As such, it has important implications for understanding the ecological contribution of fungi to aquatic food webs and related biogeochemical cycles. Y1 - 2017 U6 - https://doi.org/10.1002/lno.10545 SN - 1524-4695 SN - 1938-5390 VL - 40 SP - 282 EP - 288 PB - Waterbird SOC CY - Washington ER - TY - JOUR A1 - Taube, Robert A1 - Ganzert, Lars A1 - Grossart, Hans-Peter A1 - Gleixner, Gerd A1 - Premke, Katrin T1 - Organic matter quality structures benthic fatty acid patterns and the abundance of fungi and bacteria in temperate lakes JF - The science of the total environment : an international journal for scientific research into the environment and its relationship with man N2 - Benthic microbial communities (BMCs) play important roles in the carbon cycle of lakes, and benthic littoral zones in particular have been previously highlighted as biogeochemical hotspots. Dissolved organic matter (DOM) presents the major carbon pool in lakes, and although the effect of DOM composition on the pelagic microbial community composition is widely accepted, little is known about its effect on BMCs, particularly aquatic fungi. Therefore, we investigated the composition of benthic littoral microbial communities in twenty highly diverse lakes in northeast Germany. DOM quality was analyzed via size exclusion chromatography (SEC), fluorescence parallel factor analyses (PRAFACs) and UV-Vis spectroscopy. We determined the BMC composition and biomass using phospholipid-derived fatty acids (PLFA) and extended the interpretation to the analysis of fungi by applying a Bayesian mixed model. We present evidence that the quality of DOM structures the BMCs, which are dominated by heterotrophic bacteria and show low fungal biomass. The fungal biomass increases when the DOM pool is processed by microorganisms of allochthonous origin, whereas the opposite is true for bacteria. KW - PLFA KW - PARAFAC KW - Size exclusion chromatography (SEC) KW - Aquatic fungi KW - Stable isotopes KW - FASTAR Y1 - 2017 U6 - https://doi.org/10.1016/j.scitotenv.2017.07.256 SN - 0048-9697 SN - 1879-1026 VL - 610 SP - 469 EP - 481 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Balint, Miklos A1 - Marton, Orsolya A1 - Schatz, Marlene A1 - Düring, Rolf-Alexander A1 - Grossart, Hans-Peter T1 - Proper experimental design requires randomization/balancing of molecular ecology experiments JF - Ecology and evolution N2 - Properly designed (randomized and/or balanced) experiments are standard in ecological research. Molecular methods are increasingly used in ecology, but studies generally do not report the detailed design of sample processing in the laboratory. This may strongly influence the interpretability of results if the laboratory procedures do not account for the confounding effects of unexpected laboratory events. We demonstrate this with a simple experiment where unexpected differences in laboratory processing of samples would have biased results if randomization in DNA extraction and PCR steps do not provide safeguards. We emphasize the need for proper experimental design and reporting of the laboratory phase of molecular ecology research to ensure the reliability and interpretability of results. KW - batch effect KW - bias KW - DNA extraction KW - environmental DNA KW - laboratory practice KW - lake community KW - metabarcoding KW - nondemonic intrusions KW - PCR KW - sediment Y1 - 2018 U6 - https://doi.org/10.1002/ece3.3687 SN - 2045-7758 VL - 8 IS - 3 SP - 1786 EP - 1793 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Göritz, Anna A1 - Berger, Stella A. A1 - Gege, Peter A1 - Grossart, Hans-Peter A1 - Nejstgaard, Jens C. A1 - Riedel, Sebastian A1 - Röttgers, Rüdiger A1 - Utschig, Christian T1 - Retrieval of water constituents from hyperspectral in-situ measurements under variable cloud cover BT - a case study at Lake Stechlin (Germany) JF - Remote sensing / Molecular Diversity Preservation International (MDPI) N2 - Remote sensing and field spectroscopy of natural waters is typically performed under clear skies, low wind speeds and low solar zenith angles. Such measurements can also be made, in principle, under clouds and mixed skies using airborne or in-situ measurements; however, variable illumination conditions pose a challenge to data analysis. In the present case study, we evaluated the inversion of hyperspectral in-situ measurements for water constituent retrieval acquired under variable cloud cover. First, we studied the retrieval of Chlorophyll-a (Chl-a) concentration and colored dissolved organic matter (CDOM) absorption from in-water irradiance measurements. Then, we evaluated the errors in the retrievals of the concentration of total suspended matter (TSM), Chl-a and the absorption coefficient of CDOM from above-water reflectance measurements due to highly variable reflections at the water surface. In order to approximate cloud reflections, we extended a recent three-component surface reflectance model for cloudless atmospheres by a constant offset and compared different surface reflectance correction procedures. Our findings suggest that in-water irradiance measurements may be used for the analysis of absorbing compounds even under highly variable weather conditions. The extended surface reflectance model proved to contribute to the analysis of above-water reflectance measurements with respect to Chl-a and TSM. Results indicate the potential of this approach for all-weather monitoring. KW - remote sensing KW - inland water KW - hyperspectral measurements KW - in-situ KW - cloud KW - surface reflection KW - inversion KW - bio-optical modeling Y1 - 2018 U6 - https://doi.org/10.3390/rs10020181 SN - 2072-4292 VL - 10 IS - 2 PB - MDPI CY - Basel ER - TY - JOUR A1 - Cuadrat, Rafael R. C. A1 - Ionescu, Danny A1 - Davila, Alberto M. R. A1 - Grossart, Hans-Peter T1 - Recovering genomics clusters of secondary metabolites from lakes using genome-resolved metagenomics JF - Frontiers in microbiology N2 - Metagenomic approaches became increasingly popular in the past decades due to decreasing costs of DNA sequencing and bioinformatics development. So far, however, the recovery of long genes coding for secondary metabolites still represents a big challenge. Often, the quality of metagenome assemblies is poor, especially in environments with a high microbial diversity where sequence coverage is low and complexity of natural communities high. Recently, new and improved algorithms for binning environmental reads and contigs have been developed to overcome such limitations. Some of these algorithms use a similarity detection approach to classify the obtained reads into taxonomical units and to assemble draft genomes. This approach, however, is quite limited since it can classify exclusively sequences similar to those available (and well classified) in the databases. In this work, we used draft genomes from Lake Stechlin, north-eastern Germany, recovered by MetaBat, an efficient binning tool that integrates empirical probabilistic distances of genome abundance, and tetranucleotide frequency for accurate metagenome binning. These genomes were screened for secondary metabolism genes, such as polyketide synthases (PKS) and non-ribosomal peptide synthases (NRPS), using the Anti-SMASH and NAPDOS workflows. With this approach we were able to identify 243 secondary metabolite clusters from 121 genomes recovered from our lake samples. A total of 18 NRPS, 19 PKS, and 3 hybrid PKS/NRPS clusters were found. In addition, it was possible to predict the partial structure of several secondary metabolite clusters allowing for taxonomical classifications and phylogenetic inferences. Our approach revealed a high potential to recover and study secondary metabolites genes from any aquatic ecosystem. KW - metagenomics 2.0 KW - PKS KW - NRPS KW - freshwater KW - environmental genomics Y1 - 2018 U6 - https://doi.org/10.3389/fmicb.2018.00251 SN - 1664-302X VL - 9 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Eckert, Ester M. A1 - Di Cesare, Andrea A1 - Kettner, Marie Therese A1 - Arias-Andres, Maria A1 - Fontaneto, Diego A1 - Grossart, Hans-Peter A1 - Corno, Gianluca T1 - Microplastics increase impact of treated wastewater on freshwater microbial community JF - Environmental pollution N2 - Plastic pollution is a major global concern with several million microplastic particles entering every day freshwater ecosystems via wastewater discharge. Microplastic particles stimulate biofilm formation (plastisphere) throughout the water column and have the potential to affect microbial community structure if they accumulate in pelagic waters, especially enhancing the proliferation of biohazardous bacteria. To test this scenario, we simulated the inflow of treated wastewater into a temperate lake using a continuous culture system with a gradient of concentration of microplastic particles. We followed the effect of microplastics on the microbial community structure and on the occurrence of integrase 1 (intl), a marker associated with mobile genetic elements known as a proxy for anthropogenic effects on the spread of antimicrobial resistance genes. The abundance of intl increased in the plastisphere with increasing microplastic particle concentration, but not in the water surrounding the microplastic particles. Likewise, the microbial community on microplastic was more similar to the original wastewater community with increasing microplastic concentrations. Our results show that microplastic particles indeed promote persistence of typical indicators of microbial anthropogenic pollution in natural waters, and substantiate that their removal from treated wastewater should be prioritised. (C) 2017 Elsevier Ltd. All rights reserved. KW - Microplastics KW - Anthropogenic pollution KW - Treated wastewater KW - Freshwater microbial communities KW - Integrase 1 KW - Biofilm Y1 - 2017 U6 - https://doi.org/10.1016/j.envpol.2017.11.070 SN - 0269-7491 SN - 1873-6424 VL - 234 SP - 495 EP - 502 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Mantzouki, Evanthia A1 - Lurling, Miquel A1 - Fastner, Jutta A1 - Domis, Lisette Nicole de Senerpont A1 - Wilk-Wozniak, Elzbieta A1 - Koreiviene, Judita A1 - Seelen, Laura A1 - Teurlincx, Sven A1 - Verstijnen, Yvon A1 - Krzton, Wojciech A1 - Walusiak, Edward A1 - Karosiene, Jurate A1 - Kasperoviciene, Jurate A1 - Savadova, Ksenija A1 - Vitonyte, Irma A1 - Cillero-Castro, Carmen A1 - Budzynska, Agnieszka A1 - Goldyn, Ryszard A1 - Kozak, Anna A1 - Rosinska, Joanna A1 - Szelag-Wasielewska, Elzbieta A1 - Domek, Piotr A1 - Jakubowska-Krepska, Natalia A1 - Kwasizur, Kinga A1 - Messyasz, Beata A1 - Pelechata, Aleksandra A1 - Pelechaty, Mariusz A1 - Kokocinski, Mikolaj A1 - Garcia-Murcia, Ana A1 - Real, Monserrat A1 - Romans, Elvira A1 - Noguero-Ribes, Jordi A1 - Parreno Duque, David A1 - Fernandez-Moran, Elisabeth A1 - Karakaya, Nusret A1 - Haggqvist, Kerstin A1 - Demir, Nilsun A1 - Beklioglu, Meryem A1 - Filiz, Nur A1 - Levi, Eti E. A1 - Iskin, Ugur A1 - Bezirci, Gizem A1 - Tavsanoglu, Ulku Nihan A1 - Ozhan, Koray A1 - Gkelis, Spyros A1 - Panou, Manthos A1 - Fakioglu, Ozden A1 - Avagianos, Christos A1 - Kaloudis, Triantafyllos A1 - Celik, Kemal A1 - Yilmaz, Mete A1 - Marce, Rafael A1 - Catalan, Nuria A1 - Bravo, Andrea G. A1 - Buck, Moritz A1 - Colom-Montero, William A1 - Mustonen, Kristiina A1 - Pierson, Don A1 - Yang, Yang A1 - Raposeiro, Pedro M. A1 - Goncalves, Vitor A1 - Antoniou, Maria G. A1 - Tsiarta, Nikoletta A1 - McCarthy, Valerie A1 - Perello, Victor C. A1 - Feldmann, Tonu A1 - Laas, Alo A1 - Panksep, Kristel A1 - Tuvikene, Lea A1 - Gagala, Ilona A1 - Mankiewicz-Boczek, Joana A1 - Yagci, Meral Apaydin A1 - Cinar, Sakir A1 - Capkin, Kadir A1 - Yagci, Abdulkadir A1 - Cesur, Mehmet A1 - Bilgin, Fuat A1 - Bulut, Cafer A1 - Uysal, Rahmi A1 - Obertegger, Ulrike A1 - Boscaini, Adriano A1 - Flaim, Giovanna A1 - Salmaso, Nico A1 - Cerasino, Leonardo A1 - Richardson, Jessica A1 - Visser, Petra M. A1 - Verspagen, Jolanda M. H. A1 - Karan, Tunay A1 - Soylu, Elif Neyran A1 - Maraslioglu, Faruk A1 - Napiorkowska-Krzebietke, Agnieszka A1 - Ochocka, Agnieszka A1 - Pasztaleniec, Agnieszka A1 - Antao-Geraldes, Ana M. A1 - Vasconcelos, Vitor A1 - Morais, Joao A1 - Vale, Micaela A1 - Koker, Latife A1 - Akcaalan, Reyhan A1 - Albay, Meric A1 - Maronic, Dubravka Spoljaric A1 - Stevic, Filip A1 - Pfeiffer, Tanja Zuna A1 - Fonvielle, Jeremy Andre A1 - Straile, Dietmar A1 - Rothhaupt, Karl-Otto A1 - Hansson, Lars-Anders A1 - Urrutia-Cordero, Pablo A1 - Blaha, Ludek A1 - Geris, Rodan A1 - Frankova, Marketa A1 - Kocer, Mehmet Ali Turan A1 - Alp, Mehmet Tahir A1 - Remec-Rekar, Spela A1 - Elersek, Tina A1 - Triantis, Theodoros A1 - Zervou, Sevasti-Kiriaki A1 - Hiskia, Anastasia A1 - Haande, Sigrid A1 - Skjelbred, Birger A1 - Madrecka, Beata A1 - Nemova, Hana A1 - Drastichova, Iveta A1 - Chomova, Lucia A1 - Edwards, Christine A1 - Sevindik, Tugba Ongun A1 - Tunca, Hatice A1 - OEnem, Burcin A1 - Aleksovski, Boris A1 - Krstic, Svetislav A1 - Vucelic, Itana Bokan A1 - Nawrocka, Lidia A1 - Salmi, Pauliina A1 - Machado-Vieira, Danielle A1 - de Oliveira, Alinne Gurjao A1 - Delgado-Martin, Jordi A1 - Garcia, David A1 - Cereijo, Jose Luis A1 - Goma, Joan A1 - Trapote, Mari Carmen A1 - Vegas-Vilarrubia, Teresa A1 - Obrador, Biel A1 - Grabowska, Magdalena A1 - Karpowicz, Maciej A1 - Chmura, Damian A1 - Ubeda, Barbara A1 - Angel Galvez, Jose A1 - Ozen, Arda A1 - Christoffersen, Kirsten Seestern A1 - Warming, Trine Perlt A1 - Kobos, Justyna A1 - Mazur-Marzec, Hanna A1 - Perez-Martinez, Carmen A1 - Ramos-Rodriguez, Eloisa A1 - Arvola, Lauri A1 - Alcaraz-Parraga, Pablo A1 - Toporowska, Magdalena A1 - Pawlik-Skowronska, Barbara A1 - Niedzwiecki, Michal A1 - Peczula, Wojciech A1 - Leira, Manel A1 - Hernandez, Armand A1 - Moreno-Ostos, Enrique A1 - Maria Blanco, Jose A1 - Rodriguez, Valeriano A1 - Juan Montes-Perez, Jorge A1 - Palomino, Roberto L. A1 - Rodriguez-Perez, Estela A1 - Carballeira, Rafael A1 - Camacho, Antonio A1 - Picazo, Antonio A1 - Rochera, Carlos A1 - Santamans, Anna C. A1 - Ferriol, Carmen A1 - Romo, Susana A1 - Miguel Soria, Juan A1 - Dunalska, Julita A1 - Sienska, Justyna A1 - Szymanski, Daniel A1 - Kruk, Marek A1 - Kostrzewska-Szlakowska, Iwona A1 - Jasser, Iwona A1 - Zutinic, Petar A1 - Udovic, Marija Gligora A1 - Plenkovic-Moraj, Andelka A1 - Frak, Magdalena A1 - Bankowska-Sobczak, Agnieszka A1 - Wasilewicz, Michal A1 - Ozkan, Korhan A1 - Maliaka, Valentini A1 - Kangro, Kersti A1 - Grossart, Hans-Peter A1 - Paerl, Hans W. A1 - Carey, Cayelan C. A1 - Ibelings, Bas W. T1 - Temperature effects explain continental scale distribution of cyanobacterial toxins JF - Toxins N2 - Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains. KW - microcystin KW - anatoxin KW - cylindrospermopsin KW - temperature KW - direct effects KW - indirect effects KW - spatial distribution KW - European Multi Lake Survey Y1 - 2018 U6 - https://doi.org/10.3390/toxins10040156 SN - 2072-6651 VL - 10 IS - 4 PB - MDPI CY - Basel ER - TY - JOUR A1 - Garcia, Sarahi L. A1 - Buck, Moritz A1 - Hamilton, Joshua J. A1 - Wurzbacher, Christian A1 - Grossart, Hans-Peter A1 - McMahon, Katherine D. A1 - Eiler, Alexander T1 - Model communities hint at promiscuous metabolic linkages between ubiquitous free-living freshwater bacteria JF - mSphere N2 - Genome streamlining is frequently observed in free-living aquatic microorganisms and results in physiological dependencies between microorganisms. However, we know little about the specificity of these microbial associations. In order to examine the specificity and extent of these associations, we established mixed cultures from three different freshwater environments and analyzed the cooccurrence of organisms using a metagenomic time series. Free-living microorganisms with streamlined genomes lacking multiple biosynthetic pathways showed no clear recurring pattern in their interaction partners. Free-living freshwater bacteria form promiscuous cooperative associations. This notion contrasts with the well-documented high specificities of interaction partners in host-associated bacteria. Considering all data together, we suggest that highly abundant free-living bacterial lineages are functionally versatile in their interactions despite their distinct streamlining tendencies at the single-cell level. This metabolic versatility facilitates interactions with a variable set of community members. KW - community KW - interactions KW - metagenomics KW - microbial ecology KW - mixed cultures KW - promiscuous Y1 - 2018 U6 - https://doi.org/10.1128/mSphere.00202-18 SN - 2379-5042 VL - 3 IS - 3 PB - American Society for Microbiology CY - Washington ER - TY - JOUR A1 - Arias-Andres, Maria A1 - Kluemper, Uli A1 - Rojas-Jimenez, Keilor A1 - Grossart, Hans-Peter T1 - Microplastic pollution increases gene exchange in aquatic ecosystems JF - Environmental pollution N2 - Pollution by microplastics in aquatic ecosystems is accumulating at an unprecedented scale, emerging as a new surface for biofilm formation and gene exchange. In this study, we determined the permissiveness of aquatic bacteria towards a model antibiotic resistance plasmid, comparing communities that form biofilms on microplastics vs. those that are free-living. We used an exogenous and red-fluorescent E. coli donor strain to introduce the green-fluorescent broad-host-range plasmid pKJKS which encodes for trimethoprim resistance. We demonstrate an increased frequency of plasmid transfer in bacteria associated with microplastics compared to bacteria that are free-living or in natural aggregates. Moreover, comparison of communities grown on polycarbonate filters showed that increased gene exchange occurs in a broad range of phylogenetically-diverse bacteria. Our results indicate horizontal gene transfer in this habitat could distinctly affect the ecology of aquatic microbial communities on a global scale. The spread of antibiotic resistance through microplastics could also have profound consequences for the evolution of aquatic bacteria and poses a neglected hazard for human health. KW - Microplastics KW - Aquatic ecosystems KW - Biofilm KW - Horizontal gene transfer KW - Antibiotic resistance Y1 - 2018 U6 - https://doi.org/10.1016/j.envpol.2018.02.058 SN - 0269-7491 SN - 1873-6424 VL - 237 SP - 253 EP - 261 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Reverey, Florian A1 - Ganzert, Lars A1 - Lischeid, Gunnar A1 - Ulrich, Andreas A1 - Premke, Katrin A1 - Grossart, Hans-Peter T1 - Dry-wet cycles of kettle hole sediments leave a microbial and biogeochemical legacy JF - The science of the total environment : an international journal for scientific research into the environment and its relationship with man N2 - Understanding interrelations between an environment's hydrological past and its current biogeochemistry is necessary for the assessment of biogeochemical and microbial responses to changing hydrological conditions. The question how previous dry-wet events determine the contemporary microbial and biogeochemical state is addressed in this study. Therefore, sediments exposed to the atmosphere of areas with a different hydrological past within one kettle hole, i.e. (1) the predominantly inundated pond center, (2) the pond margin frequently desiccated for longer periods and (3) an intermediate zone, were incubated with the same rewetting treatment. Physicochemical and textural characteristics were related to structural microbial parameters regarding carbon and nitrogen turnover, i.e. abundance of bacteria and fungi, denitrifiers (targeted by the nirK und nirS functional genes) and nitrate ammonifiers (targeted by the nrfA functional gene). Our study reveals that, in combination with varying sediment texture, the hydrological history creates distinct microbial habitats with defined boundary conditions within the kettle hole, mainly driven by redox conditions, pH and organic matter (OM) composition. OM mineralization, as indicated by CO2-outgassing, was most efficient in exposed sediments with a less stable hydrological past. The potential for nitrogen retention via nitrate ammonification was highest in the hydrologically rather stable pond center, counteracting nitrogen loss due to denitrification. Therefore, the degree of hydrological stability is an important factor leaving a microbial and biogeochemical legacy, which determines carbon and nitrogen losses from small lentic freshwater systems in the long term run. KW - Desiccation KW - DNRA KW - Denitrifiers KW - Organic matter mineralization KW - Carbon KW - Nitrogen Y1 - 2018 U6 - https://doi.org/10.1016/j.scitotenv.2018.01.220 SN - 0048-9697 SN - 1879-1026 VL - 627 SP - 985 EP - 996 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Mühlenbruch, Marco A1 - Grossart, Hans-Peter A1 - Eigemann, Falk A1 - Voss, Maren T1 - Mini-review: Phytoplankton-derived polysaccharides in the marine environment and their interactions with heterotrophic bacteria JF - Environmental microbiology N2 - Within the wealth of molecules constituting marine dissolved organic matter, carbohydrates make up the largest coherent and quantifiable fraction. Their main sources are from primary producers, which release large amounts of photosynthetic products – mainly polysaccharides – directly into the surrounding water via passive and active exudation. The organic carbon and other nutrients derived from these photosynthates enrich the ‘phycosphere’ and attract heterotrophic bacteria. The rapid uptake and remineralization of dissolved free monosaccharides by heterotrophic bacteria account for the barely detectable levels of these compounds. By contrast, dissolved combined polysaccharides can reach high concentrations, especially during phytoplankton blooms. Polysaccharides are too large to be taken up directly by heterotrophic bacteria, instead requiring hydrolytic cleavage to smaller oligo- or monomers by bacteria with a suitable set of exoenzymes. The release of diverse polysaccharides by various phytoplankton taxa is generally interpreted as the deposition of excess organic material. However, these molecules likely also fulfil distinct, yet not fully understood functions, as inferred from their active modulation in terms of quality and quantity when phytoplankton becomes nutrient limited or is exposed to heterotrophic bacteria. This minireview summarizes current knowledge regarding the exudation and composition of phytoplankton-derived exopolysaccharides and acquisition of these compounds by heterotrophic bacteria. Y1 - 2018 U6 - https://doi.org/10.1111/1462-2920.14302 SN - 1462-2912 SN - 1462-2920 VL - 20 IS - 8 SP - 2671 EP - 2685 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Darwall, William A1 - Bremerich, Vanessa A1 - De Wever, Aaike A1 - Dell, Anthony I. A1 - Freyhof, Joerg A1 - Gessner, Mark O. A1 - Grossart, Hans-Peter A1 - Harrison, Ian A1 - Irvine, Ken A1 - Jähnig, Sonja C. A1 - Jeschke, Jonathan M. A1 - Lee, Jessica J. A1 - Lu, Cai A1 - Lewandowska, Aleksandra M. A1 - Monaghan, Michael T. A1 - Nejstgaard, Jens C. A1 - Patricio, Harmony A1 - Schmidt-Kloiber, Astrid A1 - Stuart, Simon N. A1 - Thieme, Michele A1 - Tockner, Klement A1 - Turak, Eren A1 - Weyl, Olaf T1 - The alliance for freshwater life BT - a global call to unite efforts for freshwater biodiversity science and conservation JF - Aquatic Conservation: Marine and Freshwater Ecosystems N2 - 1. Global pressures on freshwater ecosystems are high and rising. Viewed primarily as a resource for humans, current practices of water use have led to catastrophic declines in freshwater species and the degradation of freshwater ecosystems, including their genetic and functional diversity. Approximately three-quarters of the world's inland wetlands have been lost, one-third of the 28 000 freshwater species assessed for the International Union for Conservation of Nature (IUCN) Red List are threatened with extinction, and freshwater vertebrate populations are undergoing declines that are more rapid than those of terrestrial and marine species. This global loss continues unchecked, despite the importance of freshwater ecosystems as a source of clean water, food, livelihoods, recreation, and inspiration. 2. The causes of these declines include hydrological alterations, habitat degradation and loss, overexploitation, invasive species, pollution, and the multiple impacts of climate change. Although there are policy initiatives that aim to protect freshwater life, these are rarely implemented with sufficient conviction and enforcement. Policies that focus on the development and management of fresh waters as a resource for people almost universally neglect the biodiversity that they contain. 3. Here we introduce the Alliance for Freshwater Life, a global initiative, uniting specialists in research, data synthesis, conservation, education and outreach, and policymaking. This expert network aims to provide the critical mass required for the effective representation of freshwater biodiversity at policy meetings, to develop solutions balancing the needs of development and conservation, and to better convey the important role freshwater ecosystems play in human well-being. Through this united effort we hope to reverse this tide of loss and decline in freshwater biodiversity. We introduce several short- and medium-term actions as examples for making positive change, and invite individuals, organizations, authorities, and governments to join the Alliance for Freshwater Life. KW - biodiversity KW - conservation evaluation KW - endangered species KW - fish KW - invertebrates KW - macrophytes Y1 - 2018 U6 - https://doi.org/10.1002/aqc.2958 SN - 1052-7613 SN - 1099-0755 VL - 28 IS - 4 SP - 1015 EP - 1022 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Arias Andrés, María de Jesús A1 - Kettner, Marie Therese A1 - Miki, Takeshi A1 - Grossart, Hans-Peter T1 - Microplastics: New substrates for heterotrophic activity contribute to altering organic matter cycles in aquatic ecosystems JF - The science of the total environment : an international journal for scientific research into the environment and its relationship with man N2 - Heterotrophic microbes with the capability to process considerable amounts of organic matter can colonize microplastic particles (MP) in aquatic ecosystems. Weather colonization of microorganisms on MP will alter ecological niche and functioning of microbial communities remains still unanswered. Therefore, we compared the functional diversity of biofilms on microplastics when incubated in three lakes in northeastern Germany differing in trophy and limnological features. For all lakes, we compared heterotrophic activities of MP biofilms with those of microorganisms in the surrounding water by using Biolog (R) EcoPlates and assessed their oxygen consumption in microcosm assays with and without MP. The present study found that the total biofilm biomass was higher in the oligo-mesotrophic and dystrophic lakes than in the eutrophic lake. In all lakes, functional diversity profiles of MP biofilms consistently differed from those in the surrounding water. However, solely in the oligo-mesotrophic lake MP biofilms had a higher functional richness compared to the ambient water. These results demonstrate that the functionality and hence the ecological role of MP-associated microbial communities are context-dependent, i.e. different environments lead to substantial changes in biomass build up and heterotrophic activities of MP biofilms. We propose that MP surfaces act as new niches for aquatic microorganisms and that the constantly increasing MP pollution has the potential to globally impact carbon dynamics of pelagic environments by altering heterotrophic activities. (C) 2018 Elsevier B.V. All rights reserved. KW - Microplastics KW - Microorganisms KW - Biofilms KW - Total biomass KW - Heterotrophic activity KW - Functional diversity KW - Multi-functionality index Y1 - 2018 U6 - https://doi.org/10.1016/j.scitotenv.2018.04.199 SN - 0048-9697 SN - 1879-1026 VL - 635 SP - 1152 EP - 1159 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Mantzouki, Evanthia A1 - Campbell, James A1 - van Loon, Emiel A1 - Visser, Petra A1 - Konstantinou, Iosif A1 - Antoniou, Maria A1 - Giuliani, Gregory A1 - Machado-Vieira, Danielle A1 - de Oliveira, Alinne Gurjao A1 - Maronic, Dubravka Spoljaric A1 - Stevic, Filip A1 - Pfeiffer, Tanja Zuna A1 - Vucelic, Itana Bokan A1 - Zutinic, Petar A1 - Udovic, Marija Gligora A1 - Plenkovic-Moraj, Andelka A1 - Tsiarta, Nikoletta A1 - Blaha, Ludek A1 - Geris, Rodan A1 - Frankova, Marketa A1 - Christoffersen, Kirsten Seestern A1 - Warming, Trine Perlt A1 - Feldmann, Tonu A1 - Laas, Alo A1 - Panksep, Kristel A1 - Tuvikene, Lea A1 - Kangro, Kersti A1 - Haggqvist, Kerstin A1 - Salmi, Pauliina A1 - Arvola, Lauri A1 - Fastner, Jutta A1 - Straile, Dietmar A1 - Rothhaupt, Karl-Otto A1 - Fonvielle, Jeremy Andre A1 - Grossart, Hans-Peter A1 - Avagianos, Christos A1 - Kaloudis, Triantafyllos A1 - Triantis, Theodoros A1 - Zervou, Sevasti-Kiriaki A1 - Hiskia, Anastasia A1 - Gkelis, Spyros A1 - Panou, Manthos A1 - McCarthy, Valerie A1 - Perello, Victor C. A1 - Obertegger, Ulrike A1 - Boscaini, Adriano A1 - Flaim, Giovanna A1 - Salmaso, Nico A1 - Cerasino, Leonardo A1 - Koreiviene, Judita A1 - Karosiene, Jurate A1 - Kasperoviciene, Jurate A1 - Savadova, Ksenija A1 - Vitonyte, Irma A1 - Haande, Sigrid A1 - Skjelbred, Birger A1 - Grabowska, Magdalena A1 - Karpowicz, Maciej A1 - Chmura, Damian A1 - Nawrocka, Lidia A1 - Kobos, Justyna A1 - Mazur-Marzec, Hanna A1 - Alcaraz-Parraga, Pablo A1 - Wilk-Wozniak, Elzbieta A1 - Krzton, Wojciech A1 - Walusiak, Edward A1 - Gagala, Ilona A1 - Mankiewicz-Boczek, Joana A1 - Toporowska, Magdalena A1 - Pawlik-Skowronska, Barbara A1 - Niedzwiecki, Michal A1 - Peczula, Wojciech A1 - Napiorkowska-Krzebietke, Agnieszka A1 - Dunalska, Julita A1 - Sienska, Justyna A1 - Szymanski, Daniel A1 - Kruk, Marek A1 - Budzynska, Agnieszka A1 - Goldyn, Ryszard A1 - Kozak, Anna A1 - Rosinska, Joanna A1 - Szelag-Wasielewska, Elzbieta A1 - Domek, Piotr A1 - Jakubowska-Krepska, Natalia A1 - Kwasizur, Kinga A1 - Messyasz, Beata A1 - Pelechata, Aleksandra A1 - Pelechaty, Mariusz A1 - Kokocinski, Mikolaj A1 - Madrecka, Beata A1 - Kostrzewska-Szlakowska, Iwona A1 - Frak, Magdalena A1 - Bankowska-Sobczak, Agnieszka A1 - Wasilewicz, Michal A1 - Ochocka, Agnieszka A1 - Pasztaleniec, Agnieszka A1 - Jasser, Iwona A1 - Antao-Geraldes, Ana M. A1 - Leira, Manel A1 - Hernandez, Armand A1 - Vasconcelos, Vitor A1 - Morais, Joao A1 - Vale, Micaela A1 - Raposeiro, Pedro M. A1 - Goncalves, Vitor A1 - Aleksovski, Boris A1 - Krstic, Svetislav A1 - Nemova, Hana A1 - Drastichova, Iveta A1 - Chomova, Lucia A1 - Remec-Rekar, Spela A1 - Elersek, Tina A1 - Delgado-Martin, Jordi A1 - Garcia, David A1 - Luis Cereijo, Jose A1 - Goma, Joan A1 - Carmen Trapote, Mari A1 - Vegas-Vilarrubia, Teresa A1 - Obrador, Biel A1 - Garcia-Murcia, Ana A1 - Real, Monserrat A1 - Romans, Elvira A1 - Noguero-Ribes, Jordi A1 - Parreno Duque, David A1 - Fernandez-Moran, Elisabeth A1 - Ubeda, Barbara A1 - Angel Galvez, Jose A1 - Marce, Rafael A1 - Catalan, Nuria A1 - Perez-Martinez, Carmen A1 - Ramos-Rodriguez, Eloisa A1 - Cillero-Castro, Carmen A1 - Moreno-Ostos, Enrique A1 - Maria Blanco, Jose A1 - Rodriguez, Valeriano A1 - Juan Montes-Perez, Jorge A1 - Palomino, Roberto L. A1 - Rodriguez-Perez, Estela A1 - Carballeira, Rafael A1 - Camacho, Antonio A1 - Picazo, Antonio A1 - Rochera, Carlos A1 - Santamans, Anna C. A1 - Ferriol, Carmen A1 - Romo, Susana A1 - Soria, Juan Miguel A1 - Hansson, Lars-Anders A1 - Urrutia-Cordero, Pablo A1 - Ozen, Arda A1 - Bravo, Andrea G. A1 - Buck, Moritz A1 - Colom-Montero, William A1 - Mustonen, Kristiina A1 - Pierson, Don A1 - Yang, Yang A1 - Verspagen, Jolanda M. H. A1 - Domis, Lisette N. de Senerpont A1 - Seelen, Laura A1 - Teurlincx, Sven A1 - Verstijnen, Yvon A1 - Lurling, Miquel A1 - Maliaka, Valentini A1 - Faassen, Elisabeth J. A1 - Latour, Delphine A1 - Carey, Cayelan C. A1 - Paerl, Hans W. A1 - Torokne, Andrea A1 - Karan, Tunay A1 - Demir, Nilsun A1 - Beklioglu, Meryem A1 - Filiz, Nur A1 - Levi, Eti E. A1 - Iskin, Ugur A1 - Bezirci, Gizem A1 - Tavsanoglu, Ulku Nihan A1 - Celik, Kemal A1 - Ozhan, Koray A1 - Karakaya, Nusret A1 - Kocer, Mehmet Ali Turan A1 - Yilmaz, Mete A1 - Maraslioglu, Faruk A1 - Fakioglu, Ozden A1 - Soylu, Elif Neyran A1 - Yagci, Meral Apaydin A1 - Cinar, Sakir A1 - Capkin, Kadir A1 - Yagci, Abdulkadir A1 - Cesur, Mehmet A1 - Bilgin, Fuat A1 - Bulut, Cafer A1 - Uysal, Rahmi A1 - Koker, Latife A1 - Akcaalan, Reyhan A1 - Albay, Meric A1 - Alp, Mehmet Tahir A1 - Ozkan, Korhan A1 - Sevindik, Tugba Ongun A1 - Tunca, Hatice A1 - Onem, Burcin A1 - Richardson, Jessica A1 - Edwards, Christine A1 - Bergkemper, Victoria A1 - Beirne, Eilish A1 - Cromie, Hannah A1 - Ibelings, Bastiaan W. T1 - Data Descriptor: A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins JF - Scientific Data N2 - Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment. KW - Climate-change ecology KW - Limnology KW - Water resources Y1 - 2018 U6 - https://doi.org/10.1038/sdata.2018.226 SN - 2052-4463 VL - 5 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Bizic-Ionescu, Mina A1 - Ionescu, Danny A1 - Grossart, Hans-Peter T1 - Organic Particles: Heterogeneous Hubs for Microbial Interactions in Aquatic Ecosystems JF - Frontiers in microbiology N2 - The dynamics and activities of microbes colonizing organic particles (hereafter particles) greatly determine the efficiency of the aquatic carbon pump. Current understanding is that particle composition, structure and surface properties, determined mostly by the forming organisms and organic matter, dictate initial microbial colonization and the subsequent rapid succession events taking place as organic matter lability and nutrient content change with microbial degradation. We applied a transcriptomic approach to assess the role of stochastic events on initial microbial colonization of particles. Furthermore, we asked whether gene expression corroborates rapid changes in carbon-quality. Commonly used size fractionated filtration averages thousands of particles of different sizes, sources, and ages. To overcome this drawback, we used replicate samples consisting each of 3–4 particles of identical source and age and further evaluated the consequences of averaging 10–1000s of particles. Using flow-through rolling tanks we conducted long-term experiments at near in situ conditions minimizing the biasing effects of closed incubation approaches often referred to as “the bottle-effect.” In our open flow-through rolling tank system, however, active microbial communities were highly heterogeneous despite an identical particle source, suggesting random initial colonization. Contrasting previous reports using closed incubation systems, expression of carbon utilization genes didn’t change after 1 week of incubation. Consequently, we suggest that in nature, changes in particle-associated community related to carbon availability are much slower (days to weeks) due to constant supply of labile, easily degradable organic matter. Initial, random particle colonization seems to be subsequently altered by multiple organismic interactions shaping microbial community interactions and functional dynamics. Comparative analysis of thousands particles pooled togethers as well as pooled samples suggests that mechanistic studies of microbial dynamics should be done on single particles. The observed microbial heterogeneity and inter-organismic interactions may have important implications for evolution and biogeochemistry in aquatic systems. KW - particle-associated bacteria KW - microbial communities KW - inter- and intra-species interactions KW - antagonism KW - phage KW - transcriptome Y1 - 2018 U6 - https://doi.org/10.3389/fmicb.2018.02569 SN - 1664-302X VL - 9 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Van den Wyngaert, Silke A1 - Rojas-Jimenez, Keilor A1 - Seto, Kensuke A1 - Kagami, Maiko A1 - Grossart, Hans-Peter T1 - Diversity and Hidden Host Specificity of Chytrids Infecting Colonial Volvocacean Algae JF - Journal of Eukaryotic Microbiology N2 - Chytrids are zoosporic fungi that play an important, but yet understudied, ecological role in aquatic ecosystems. Many chytrid species have been morphologically described as parasites on phytoplankton. However, the majority of them have rarely been isolated and lack DNA sequence data. In this study we isolated and cultivated three parasitic chytrids, infecting a common volvocacean host species, Yamagishiella unicocca. To identify the chytrids, we characterized morphology and life cycle, and analyzed phylogenetic relationships based on 18S and 28S rDNA genes. Host range and specificity of the chytrids was determined by cross-infection assays with host strains, characterized by rbcL and ITS markers. We were able to confirm the identity of two chytrid strains as Endocoenobium eudorinae Ingold and Dangeardia mamillata Schroder and described the third chytrid strain as Algomyces stechlinensis gen. et sp. nov. The three chytrids were assigned to novel and phylogenetically distant clades within the phylum Chytridiomycota, each exhibiting different host specificities. By integrating morphological and molecular data of both the parasitic chytrids and their respective host species, we unveiled cryptic host-parasite associations. This study highlights that a high prevalence of (pseudo)cryptic diversity requires molecular characterization of both phytoplankton host and parasitic chytrid to accurately identify and compare host range and specificity, and to study phytoplankton-chytrid interactions in general. KW - Chytridiomycota KW - Dangeardia mamillata KW - Endocoenobium eudorinae KW - fungal parasites KW - life cycle KW - phytoplankton Y1 - 2018 U6 - https://doi.org/10.1111/jeu.12632 SN - 1066-5234 SN - 1550-7408 VL - 65 IS - 6 SP - 870 EP - 881 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Bachmann, Jennifer A1 - Heimbach, Tabea A1 - Hassenrück, Christiane A1 - Kopprio, German A. A1 - Iversen, Morten Hvitfeldt A1 - Grossart, Hans-Peter A1 - Gärdes, Astrid T1 - Environmental Drivers of Free-Living vs. Particle-Attached Bacterial Community Composition in the Mauritania Upwelling System JF - Frontiers in microbiology N2 - Saharan dust input and seasonal upwelling along North-West Africa provide a model system for studying microbial processes related to the export and recycling of nutrients. This study offers the first molecular characterization of prokaryotic particle-attached (PA; > 3.0 mu m) and free-living (FL; 0.2-3.0 mu m) players in this important ecosystem during August 2016. Environmental drivers for alpha-diversity, bacterial community composition, and differences between FL and PA fractions were identified. The ultra-oligotrophic waters off Senegal were dominated by Cyanobacteria while higher relative abundances of Alphaproteobacteria, Bacteroidetes, Verrucomicrobia, and Planctomycetes (known particle-degraders) occurred in the upwelling area. Temperature, proxy for different water masses, was the best predictor for changes in FL communities. PA community variation was best explained by temperature and ammonium. Bray Curtis dissimilarities between FL and PA were generally very high and correlated with temperature and salinity in surface waters. Greatest similarities between FL and PA occurred at the deep chlorophyll maximum, where bacterial substrate availability was likely highest. This indicates that environmental drivers do not only influence changes among FL and PA communities but also differences between them. This could provide an explanation for contradicting results obtained by different studies regarding the dissimilarity/similarity between FL and PA communities and their biogeochemical functions. KW - prokaryotes KW - biodiversity KW - microbial ecology KW - alpha diversity KW - Bray Curtis dissimilarity KW - temperature KW - salinity KW - 16S rRNA Illumina amplicon sequencing Y1 - 2018 U6 - https://doi.org/10.3389/fmicb.2018.02836 SN - 1664-302X VL - 9 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Mantzouki, Evanthia A1 - Beklioglu, Meryem A1 - Brookes, Justin D. A1 - Domis, Lisette Nicole de Senerpont A1 - Dugan, Hilary A. A1 - Doubek, Jonathan P. A1 - Grossart, Hans-Peter A1 - Nejstgaard, Jens C. A1 - Pollard, Amina I. A1 - Ptacnik, Robert A1 - Rose, Kevin C. A1 - Sadro, Steven A1 - Seelen, Laura A1 - Skaff, Nicholas K. A1 - Teubner, Katrin A1 - Weyhenmeyer, Gesa A. A1 - Ibelings, Bastiaan W. T1 - Snapshot surveys for lake monitoring, more than a shot in the dark JF - Frontiers in Ecology and Evolution KW - multi-lake snapshot surveys KW - lake monitoring KW - Nyquist-shannon sampling theorem KW - space-for-time substitution KW - phytoplankton ecology Y1 - 2018 U6 - https://doi.org/10.3389/fevo.2018.00201 SN - 2296-701X VL - 6 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Bálint, Miklós A1 - Pfenninger, Markus A1 - Grossart, Hans-Peter A1 - Taberlet, Pierre A1 - Vellend, Mark A1 - Leibold, Mathew A. A1 - Englund, Goran A1 - Bowler, Diana T1 - Environmental DNA time series in ecology JF - Trends in ecology & evolution N2 - Ecological communities change in time and space, but long-term dynamics at the century-to-millennia scale are poorly documented due to lack of relevant data sets. Nevertheless, understanding long-term dynamics is important for explaining present-day biodiversity patterns and placing conservation goals in a historical context. Here, we use recent examples and new perspectives to highlight how environmental DNA (eDNA) is starting to provide a powerful new source of temporal data for research questions that have so far been overlooked, by helping to resolve the ecological dynamics of populations, communities, and ecosystems over hundreds to thousands of years. We give examples of hypotheses that may be addressed by temporal eDNA biodiversity data, discuss possible research directions, and outline related challenges. Y1 - 2018 U6 - https://doi.org/10.1016/j.tree.2018.09.003 SN - 0169-5347 SN - 1872-8383 VL - 33 IS - 12 SP - 945 EP - 957 PB - Elsevier CY - London ER - TY - JOUR A1 - Cook, Katherine V. A1 - Li, Chuang A1 - Cai, Haiyuan A1 - Krumholz, Lee R. A1 - Hambright, K. David A1 - Paerl, Hans W. A1 - Steffen, Morgan M. A1 - Wilson, Alan E. A1 - Burford, Michele A. A1 - Grossart, Hans-Peter A1 - Hamilton, David P. A1 - Jiang, Helong A1 - Sukenik, Assaf A1 - Latour, Delphine A1 - Meyer, Elisabeth I. A1 - Padisak, Judit A1 - Qin, Boqiang A1 - Zamor, Richard M. A1 - Zhu, Guangwei T1 - The global Microcystis interactome JF - Limnology and oceanography N2 - Bacteria play key roles in the function and diversity of aquatic systems, but aside from study of specific bloom systems, little is known about the diversity or biogeography of bacteria associated with harmful cyanobacterial blooms (cyanoHABs). CyanoHAB species are known to shape bacterial community composition and to rely on functions provided by the associated bacteria, leading to the hypothesized cyanoHAB interactome, a coevolved community of synergistic and interacting bacteria species, each necessary for the success of the others. Here, we surveyed the microbiome associated with Microcystis aeruginosa during blooms in 12 lakes spanning four continents as an initial test of the hypothesized Microcystis interactome. We predicted that microbiome composition and functional potential would be similar across blooms globally. Our results, as revealed by 16S rRNA sequence similarity, indicate that M. aeruginosa is cosmopolitan in lakes across a 280 degrees longitudinal and 90 degrees latitudinal gradient. The microbiome communities were represented by a wide range of operational taxonomic units and relative abundances. Highly abundant taxa were more related and shared across most sites and did not vary with geographic distance, thus, like Microcystis, revealing no evidence for dispersal limitation. High phylogenetic relatedness, both within and across lakes, indicates that microbiome bacteria with similar functional potential were associated with all blooms. While Microcystis and the microbiome bacteria shared many genes, whole-community metagenomic analysis revealed a suite of biochemical pathways that could be considered complementary. Our results demonstrate a high degree of similarity across global Microcystis blooms, thereby providing initial support for the hypothesized Microcystis interactome. Y1 - 2019 U6 - https://doi.org/10.1002/lno.11361 SN - 0024-3590 SN - 1939-5590 VL - 65 SP - S194 EP - S207 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Fasching, Christina A1 - Akotoye, Christian A1 - Bižić, Mina A1 - Fonvielle, Jeremy Andre A1 - Ionescu, Danny A1 - Mathavarajah, Sabateeshan A1 - Zoccarato, Luca A1 - Walsh, David A. A1 - Grossart, Hans-Peter A1 - Xenopoulos, Marguerite A. T1 - Linking stream microbial community functional genes to dissolved organic matter and inorganic nutrients JF - Limnology and oceanography N2 - There is now increasing evidence for the importance of microbial regulation of biogeochemical cycling in streams. Resource availability shapes microbial community structure, but less is known about how landscape-mediated availability of nutrients and carbon can control microbial functions in streams. Using comparative metagenomics, we examined the relationship between microbial functional genes and composition of dissolved organic matter (DOM), nutrients, and suspended microbial communities in 11 streams, divided into three groups based on the predominant land cover category (agriculture, forested, or wetland). Using weighted gene co-occurrence network analysis, we identified clusters of functions related to DOM composition, agricultural land use, and/or wetland and forest land cover. Wetland-dominated streams were characterized by functions related to nitrogen metabolism and processing of aromatic carbon compounds, with strong positive correlations with dissolved organic carbon concentration and DOM aromaticity. Forested streams were characterized by metabolic functions related to monomer uptake and carbohydrates, such as mannose and fructose metabolism. In agricultural streams, microbial functions were correlated with more labile, protein-like DOM, PO4, and NO3, likely reflecting functional adaptation to labile DOM and higher nutrient concentrations. Distinct changes in the functional composition and loss of functional diversity of microorganisms became evident when comparing natural to agricultural catchments. Although all streams showed signs of functional redundancy, loss of species richness per function in agricultural catchments suggests that microbial functions in natural catchments may be more resilient to disturbance. Our results provide new insight into microbial community functions involved in nutrient and carbon biogeochemical cycles and their dependence on specific environmental settings. Y1 - 2019 U6 - https://doi.org/10.1002/lno.11356 SN - 0024-3590 SN - 1939-5590 VL - 65 SP - S71 EP - S87 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Grossart, Hans-Peter A1 - Massana, Ramon A1 - McMahon, Katherine D. A1 - Walsh, David A. T1 - Linking metagenomics to aquatic microbial ecology and biogeochemical cycles JF - Limnology and oceanography N2 - Microbial communities are essential components of aquatic ecosystems through their contribution to food web dynamics and biogeochemical processes. Aquatic microbial diversity is immense and a general challenge is to understand how metabolism and interactions of single organisms shape microbial community dynamics and ecosystem-scale biogeochemical transformations. Metagenomic approaches have developed rapidly, and proven to be powerful in linking microbial community dynamics to biogeochemical processes. In this review, we provide an overview of metagenomic approaches, followed by a discussion on some recent insights they have provided, including those in this special issue. These include the discovery of new taxa and metabolisms in aquatic microbiomes, insights into community assembly and functional ecology as well as evolutionary processes shaping microbial genomes and microbiomes, and the influence of human activities on aquatic microbiomes. Given that metagenomics can now be considered a mature technology where data generation and descriptive analyses are relatively routine and informative, we then discuss metagenomic-enabled research avenues to further link microbial dynamics to biogeochemical processes. These include the integration of metagenomics into well-designed ecological experiments, the use of metagenomics to inform and validate metabolic and biogeochemical models, and the pressing need for ecologically relevant model organisms and simple microbial systems to better interpret the taxonomic and functional information integrated in metagenomes. These research avenues will contribute to a more mechanistic and predictive understanding of links between microbial dynamics and biogeochemical cycles. Owing to rapid climate change and human impacts on aquatic ecosystems, the urgency of such an understanding has never been greater. Y1 - 2019 U6 - https://doi.org/10.1002/lno.11382 SN - 0024-3590 SN - 1939-5590 VL - 65 SP - S2 EP - S20 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Block, Benjamin D. A1 - Denfeld, Blaize A. A1 - Stockwell, Jason D. A1 - Flaim, Giovanna A1 - Grossart, Hans-Peter A1 - Knoll, Lesley B. A1 - Maier, Dominique B. A1 - North, Rebecca L. A1 - Rautio, Milla A1 - Rusak, James A. A1 - Sadro, Steve A1 - Weyhenmeyer, Gesa A. A1 - Bramburger, Andrew J. A1 - Branstrator, Donn K. A1 - Salonen, Kalevi A1 - Hampton, Stephanie E. T1 - The unique methodological challenges of winter limnology JF - Limnology and Oceanography: Methods N2 - Winter is an important season for many limnological processes, which can range from biogeochemical transformations to ecological interactions. Interest in the structure and function of lake ecosystems under ice is on the rise. Although limnologists working at polar latitudes have a long history of winter work, the required knowledge to successfully sample under winter conditions is not widely available and relatively few limnologists receive formal training. In particular, the deployment and operation of equipment in below 0 degrees C temperatures pose considerable logistical and methodological challenges, as do the safety risks of sampling during the ice-covered period. Here, we consolidate information on winter lake sampling and describe effective methods to measure physical, chemical, and biological variables in and under ice. We describe variation in snow and ice conditions and discuss implications for sampling logistics and safety. We outline commonly encountered methodological challenges and make recommendations for best practices to maximize safety and efficiency when sampling through ice or deploying instruments in ice-covered lakes. Application of such practices over a broad range of ice-covered lakes will contribute to a better understanding of the factors that regulate lakes during winter and how winter conditions affect the subsequent ice-free period. Y1 - 2018 U6 - https://doi.org/10.1002/lom3.10295 SN - 1541-5856 VL - 17 IS - 1 SP - 42 EP - 57 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Kolmakova, Olesya V. A1 - Gladyshev, Michail I. A1 - Fonvielle, Jeremy Andre A1 - Ganzert, Lars A1 - Hornick, Thomas A1 - Grossart, Hans-Peter T1 - Effects of zooplankton carcasses degradation on freshwater bacterial community composition and implications for carbon cycling JF - Environmental microbiology N2 - Non-predatory mortality of zooplankton provides an abundant, yet, little studied source of high quality labile organic matter (LOM) in aquatic ecosystems. Using laboratory microcosms, we followed the decomposition of organic carbon of fresh C-13-labelled Daphnia carcasses by natural bacterioplankton. The experimental setup comprised blank microcosms, that is, artificial lake water without any organic matter additions (B), and microcosms either amended with natural humic matter (H), fresh Daphnia carcasses (D) or both, that is, humic matter and Daphnia carcasses (HD). Most of the carcass carbon was consumed and respired by the bacterial community within 15 days of incubation. A shift in the bacterial community composition shaped by labile carcass carbon and by humic matter was observed. Nevertheless, we did not observe a quantitative change in humic matter degradation by heterotrophic bacteria in the presence of LOM derived from carcasses. However, carcasses were the main factor driving the bacterial community composition suggesting that the presence of large quantities of dead zooplankton might affect the carbon cycling in aquatic ecosystems. Our results imply that organic matter derived from zooplankton carcasses is efficiently remineralized by a highly specific bacterial community, but does not interfere with the bacterial turnover of more refractory humic matter. Y1 - 2018 U6 - https://doi.org/10.1111/1462-2920.14418 SN - 1462-2912 SN - 1462-2920 VL - 21 IS - 1 SP - 34 EP - 49 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Tiegs, Scott D. A1 - Costello, David M. A1 - Isken, Mark W. A1 - Woodward, Guy A1 - McIntyre, Peter B. A1 - Gessner, Mark O. A1 - Chauvet, Eric A1 - Griffiths, Natalie A. A1 - Flecker, Alex S. A1 - Acuna, Vicenc A1 - Albarino, Ricardo A1 - Allen, Daniel C. A1 - Alonso, Cecilia A1 - Andino, Patricio A1 - Arango, Clay A1 - Aroviita, Jukka A1 - Barbosa, Marcus V. M. A1 - Barmuta, Leon A. A1 - Baxter, Colden V. A1 - Bell, Thomas D. C. A1 - Bellinger, Brent A1 - Boyero, Luz A1 - Brown, Lee E. A1 - Bruder, Andreas A1 - Bruesewitz, Denise A. A1 - Burdon, Francis J. A1 - Callisto, Marcos A1 - Canhoto, Cristina A1 - Capps, Krista A. A1 - Castillo, Maria M. A1 - Clapcott, Joanne A1 - Colas, Fanny A1 - Colon-Gaud, Checo A1 - Cornut, Julien A1 - Crespo-Perez, Veronica A1 - Cross, Wyatt F. A1 - Culp, Joseph M. A1 - Danger, Michael A1 - Dangles, Olivier A1 - de Eyto, Elvira A1 - Derry, Alison M. A1 - Diaz Villanueva, Veronica A1 - Douglas, Michael M. A1 - Elosegi, Arturo A1 - Encalada, Andrea C. A1 - Entrekin, Sally A1 - Espinosa, Rodrigo A1 - Ethaiya, Diana A1 - Ferreira, Veronica A1 - Ferriol, Carmen A1 - Flanagan, Kyla M. A1 - Fleituch, Tadeusz A1 - Shah, Jennifer J. Follstad A1 - Frainer, Andre A1 - Friberg, Nikolai A1 - Frost, Paul C. A1 - Garcia, Erica A. A1 - Lago, Liliana Garcia A1 - Garcia Soto, Pavel Ernesto A1 - Ghate, Sudeep A1 - Giling, Darren P. A1 - Gilmer, Alan A1 - Goncalves, Jose Francisco A1 - Gonzales, Rosario Karina A1 - Graca, Manuel A. S. A1 - Grace, Mike A1 - Grossart, Hans-Peter A1 - Guerold, Francois A1 - Gulis, Vlad A1 - Hepp, Luiz U. A1 - Higgins, Scott A1 - Hishi, Takuo A1 - Huddart, Joseph A1 - Hudson, John A1 - Imberger, Samantha A1 - Iniguez-Armijos, Carlos A1 - Iwata, Tomoya A1 - Janetski, David J. A1 - Jennings, Eleanor A1 - Kirkwood, Andrea E. A1 - Koning, Aaron A. A1 - Kosten, Sarian A1 - Kuehn, Kevin A. A1 - Laudon, Hjalmar A1 - Leavitt, Peter R. A1 - Lemes da Silva, Aurea L. A1 - Leroux, Shawn J. A1 - Leroy, Carri J. A1 - Lisi, Peter J. A1 - MacKenzie, Richard A1 - Marcarelli, Amy M. A1 - Masese, Frank O. A1 - Mckie, Brendan G. A1 - Oliveira Medeiros, Adriana A1 - Meissner, Kristian A1 - Milisa, Marko A1 - Mishra, Shailendra A1 - Miyake, Yo A1 - Moerke, Ashley A1 - Mombrikotb, Shorok A1 - Mooney, Rob A1 - Moulton, Tim A1 - Muotka, Timo A1 - Negishi, Junjiro N. A1 - Neres-Lima, Vinicius A1 - Nieminen, Mika L. A1 - Nimptsch, Jorge A1 - Ondruch, Jakub A1 - Paavola, Riku A1 - Pardo, Isabel A1 - Patrick, Christopher J. A1 - Peeters, Edwin T. H. M. A1 - Pozo, Jesus A1 - Pringle, Catherine A1 - Prussian, Aaron A1 - Quenta, Estefania A1 - Quesada, Antonio A1 - Reid, Brian A1 - Richardson, John S. A1 - Rigosi, Anna A1 - Rincon, Jose A1 - Risnoveanu, Geta A1 - Robinson, Christopher T. A1 - Rodriguez-Gallego, Lorena A1 - Royer, Todd V. A1 - Rusak, James A. A1 - Santamans, Anna C. A1 - Selmeczy, Geza B. A1 - Simiyu, Gelas A1 - Skuja, Agnija A1 - Smykla, Jerzy A1 - Sridhar, Kandikere R. A1 - Sponseller, Ryan A1 - Stoler, Aaron A1 - Swan, Christopher M. A1 - Szlag, David A1 - Teixeira-de Mello, Franco A1 - Tonkin, Jonathan D. A1 - Uusheimo, Sari A1 - Veach, Allison M. A1 - Vilbaste, Sirje A1 - Vought, Lena B. M. A1 - Wang, Chiao-Ping A1 - Webster, Jackson R. A1 - Wilson, Paul B. A1 - Woelfl, Stefan A1 - Xenopoulos, Marguerite A. A1 - Yates, Adam G. A1 - Yoshimura, Chihiro A1 - Yule, Catherine M. A1 - Zhang, Yixin X. A1 - Zwart, Jacob A. T1 - Global patterns and drivers of ecosystem functioning in rivers and riparian zones JF - Science Advances N2 - River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented “next-generation biomonitoring” by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale. Y1 - 2019 U6 - https://doi.org/10.1126/sciadv.aav0486 SN - 2375-2548 VL - 5 IS - 1 PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Batista, A. M. M. A1 - Woodhouse, Jason Nicholas A1 - Grossart, Hans-Peter A1 - Giani, A. T1 - Methanogenic archaea associated to Microcystis sp. in field samples and in culture JF - Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica N2 - Cyanobacterial mass developments impact the community composition of heterotrophic microorganisms with far-reaching consequences for biogeochemical and energy cycles of freshwater ecosystems including reservoirs. Here we sought to evaluate the temporal stability of methanogenic archaea in the water column and further scrutinize their associations with cyanobacteria. Monthly samples were collected from October 2009 to December 2010 in hypereutrophic Pampulha reservoir with permanently blooming cyanobacteria, and from January to December 2011 in oligotrophic Volta Grande reservoir with only sporadic cyanobacteria incidence. The presence of archaea in cyanobacterial cultures was investigated by screening numerous strains of Microcystis spp. from these reservoirs as well as from lakes in Europe, Asia, and North-America. We consistently determined the occurrence of archaea, in particular methanogenic archaea, in both reservoirs throughout the year. However, archaea were only associated with two strains (Microcystis sp. UFMG 165 and UFMG 175) recently isolated from these reservoirs. These findings do not implicate archaea in the occurrence of methane in the epilimnion of inland waters, but rather serve to highlight the potential of microhabitats associated with particles, including phytoplankton, to shelter unique microbial communities. KW - Cyanobacteria KW - Methanogenic archaea KW - Bacterial community composition KW - Microcystis sp KW - Tropical reservoir Y1 - 2018 U6 - https://doi.org/10.1007/s10750-018-3655-3 SN - 0018-8158 SN - 1573-5117 VL - 831 IS - 1 SP - 163 EP - 172 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Arias-Andres, Maria A1 - Rojas-Jimenez, Keilor A1 - Grossart, Hans-Peter T1 - Collateral effects of microplastic pollution on aquatic microorganisms BT - An ecological perspective JF - Trends in Analytical Chemistry N2 - Microplastics (MP) provide a unique and extensive surface for microbial colonization in aquatic ecosystems. The formation of microorganism-microplastic complexes, such as biofilms, maximizes the degradation of organic matter and horizontal gene transfer. In this context, MP affect the structure and function of microbial communities, which in turn render the physical and chemical fate of MP. This new paradigm generates challenges for microbiology, ecology, and ecotoxicology. Dispersal of MP is concomitant with that of their associated microorganisms and their mobile genetic elements, including antibiotic resistance genes, islands of pathogenicity, and diverse metabolic pathways. Functional changes in aquatic microbiomes can alter carbon metabolism and food webs, with unknown consequences on higher organisms or human microbiomes and hence health. Here, we examine a variety of effects of MP pollution from the microbial ecology perspective, whose repercussions on aquatic ecosystems begin to be unraveled. (C) 2018 Elsevier B.V. All rights reserved. KW - Microplastics (MP) KW - Biofilms KW - HGT KW - Microbial ecology KW - Carbon cycling KW - Aquatic ecosystems KW - Health risk assessment Y1 - 2018 U6 - https://doi.org/10.1016/j.trac.2018.11.041 SN - 0165-9936 SN - 1879-3142 VL - 112 SP - 234 EP - 240 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Steger, Kristin A1 - Kim, Amy Taeyen A1 - Ganzert, Lars A1 - Grossart, Hans-Peter A1 - Smart, David R. T1 - Floodplain soil and its bacterial composition are strongly affected by depth JF - FEMS microbiology ecology N2 - We studied bacterial abundance and community structure of five soil cores using high-throughput sequencing of the 16S rRNA gene. Shifts in the soil bacterial composition were more pronounced within a vertical profile than across the landscape. Soil organic carbon (SOC) and nitrogen (N) concentrations decreased exponentially with soil depth and revealed a buried carbon-rich horizon between 0.8 and 1.3 m across all soil cores. This buried horizon was phylogenetically similar to its surrounding subsoils supporting the idea that the type of carbon, not necessarily the amount of carbon was driving the apparent similarities. In contrast to other studies, Nitrospirae was one of our major phyla with relatively high abundances throughout the soil profile except for the surface soil. Although depth is the major driver shaping soil bacterial community structure, positive correlations with SOC and N concentrations, however, were revealed with the bacterial abundance of Acidobacteria, one of the major, and Gemmatimonadetes, one of the minor phyla in our study. Our study showed that bacterial diversity in soils below 2.0 m can be still as high if not higher than in the above laying subsurface soil suggesting that various bacteria throughout the soil profile influence major biogeochemical processes in floodplain soils. KW - 16S rRNA gene sequencing KW - alluvial soil KW - buried horizon KW - Nitrospirae KW - soil bacterial diversity KW - SOC Y1 - 2019 U6 - https://doi.org/10.1093/femsec/fiz014 SN - 0168-6496 SN - 1574-6941 VL - 95 IS - 3 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Numberger, Daniela A1 - Riedel, Thomas A1 - McEwen, Gayle A1 - Nübel, Ulrich A1 - Frentrup, Martinique A1 - Schober, Isabel A1 - Bunk, Boyke A1 - Spröer, Cathrin A1 - Overmann, Jörg A1 - Grossart, Hans-Peter A1 - Greenwood, Alex D. T1 - Genomic analysis of three Clostridioides difficile isolates from urban water sources JF - Anaerobe N2 - We investigated inflow of a wastewater treatment plant and sediment of an urban lake for the presence of Clostridioides difficile by cultivation and PCR. Among seven colonies we sequenced the complete genomes of three: two non-toxigenic isolates from wastewater and one toxigenic isolate from the urban lake. For all obtained isolates, a close genomic relationship with human-derived isolates was observed. (C) 2019 Elsevier Ltd. All rights reserved. KW - Clostridioides difficile KW - Genomes KW - Sediment KW - Wastewater Y1 - 2019 U6 - https://doi.org/10.1016/j.anaerobe.2019.01.002 SN - 1075-9964 SN - 1095-8274 VL - 56 SP - 22 EP - 26 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Numberger, Daniela A1 - Dreier, Carole A1 - Vullioud, Colin A1 - Gabriel, Gülsah A1 - Greenwood, Alex D. A1 - Grossart, Hans-Peter T1 - Recovery of influenza a viruses from lake water and sediments by experimental inoculation JF - PLoS one N2 - Influenza A viruses (IAV) are zoonotic pathogens relevant to human, domestic animal and wildlife health. Many avian IAVs are transmitted among waterfowl via a faecal-oral-route. Therefore, environmental water where waterfowl congregate may play an important role in the ecology and epidemiology of avian IAV. Water and sediment may sustain and transmit virus among individuals or species. It is unclear at what concentrations waterborne viruses are infectious or remain detectable. To address this, we performed lake water and sediment dilution experiments with varying concentrations or infectious doses of four IAV strains from seal, turkey, duck and gull. To test for infectivity of the IAV strains in a concentration dependent manner, we applied cultivation to specific pathogen free (SPF) embryonated chicken eggs and Madin-Darby Canine Kidney (MDCK) cells. IAV recovery was more effective from embryonated chicken eggs than MDCK cells for freshwater lake dilutions, whereas, MDCK cells were more effective for viral recovery from sediment samples. Low infectious dose (1 PFU/200 mu L) was sufficient in most cases to detect and recover IAV from lake water dilutions. Sediment required higher initial infectious doses (>= 100 PFU/200 mu L). Y1 - 2019 U6 - https://doi.org/10.1371/journal.pone.0216880 SN - 1932-6203 VL - 14 IS - 5 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Grossart, Hans-Peter A1 - Van den Wyngaert, Silke A1 - Kagami, Maiko A1 - Wurzbacher, Christian A1 - Cunliffe, Michael A1 - Rojas-Jimenz, Keilor T1 - Fungi in aquatic ecosystems JF - Nature reviews. Microbiology N2 - Fungi are phylogenetically and functionally diverse ubiquitous components of almost all ecosystems on Earth, including aquatic environments stretching from high montane lakes down to the deep ocean. Aquatic ecosystems, however, remain frequently overlooked as fungal habitats, although fungi potentially hold important roles for organic matter cycling and food web dynamics. Recent methodological improvements have facilitated a greater appreciation of the importance of fungi in many aquatic systems, yet a conceptual framework is still missing. In this Review, we conceptualize the spatiotemporal dimensions, diversity, functions and organismic interactions of fungi in structuring aquatic food webs. We focus on currently unexplored fungal diversity, highlighting poorly understood ecosystems, including emerging artificial aquatic habitats. Y1 - 2019 U6 - https://doi.org/10.1038/s41579-019-0175-8 SN - 1740-1526 SN - 1740-1534 VL - 17 IS - 6 SP - 339 EP - 354 PB - Nature Publ. Group CY - Basingstoke ER - TY - GEN A1 - Wurzbacher, Christian A1 - Fuchs, Andrea A1 - Attermeyer, Katrin A1 - Frindte, Katharina A1 - Grossart, Hans-Peter A1 - Hupfer, Michael A1 - Casper, Peter A1 - Monaghan, Michael T. T1 - Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Background Lake sediments harbor diverse microbial communities that cycle carbon and nutrients while being constantly colonized and potentially buried by organic matter sinking from the water column. The interaction of activity and burial remained largely unexplored in aquatic sediments. We aimed to relate taxonomic composition to sediment biogeochemical parameters, test whether community turnover with depth resulted from taxonomic replacement or from richness effects, and to provide a basic model for the vertical community structure in sediments. Methods We analyzed four replicate sediment cores taken from 30-m depth in oligo-mesotrophic Lake Stechlin in northern Germany. Each 30-cm core spanned ca. 170 years of sediment accumulation according to 137Cs dating and was sectioned into layers 1–4 cm thick. We examined a full suite of biogeochemical parameters and used DNA metabarcoding to examine community composition of microbial Archaea, Bacteria, and Eukaryota. Results Community β-diversity indicated nearly complete turnover within the uppermost 30 cm. We observed a pronounced shift from Eukaryota- and Bacteria-dominated upper layers (<5 cm) to Bacteria-dominated intermediate layers (5–14 cm) and to deep layers (>14 cm) dominated by enigmatic Archaea that typically occur in deep-sea sediments. Taxonomic replacement was the prevalent mechanism in structuring the community composition and was linked to parameters indicative of microbial activity (e.g., CO2 and CH4 concentration, bacterial protein production). Richness loss played a lesser role but was linked to conservative parameters (e.g., C, N, P) indicative of past conditions. Conclusions By including all three domains, we were able to directly link the exponential decay of eukaryotes with the active sediment microbial community. The dominance of Archaea in deeper layers confirms earlier findings from marine systems and establishes freshwater sediments as a potential low-energy environment, similar to deep sea sediments. We propose a general model of sediment structure and function based on microbial characteristics and burial processes. An upper “replacement horizon” is dominated by rapid taxonomic turnover with depth, high microbial activity, and biotic interactions. A lower “depauperate horizon” is characterized by low taxonomic richness, more stable “low-energy” conditions, and a dominance of enigmatic Archaea. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1111 KW - Archaea KW - Eukaryota KW - Bacteria KW - community KW - freshwater KW - lake KW - DNA metabarcoding KW - beta-diversity KW - sediment KW - turnover Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431965 SN - 1866-8372 IS - 1111 ER - TY - JOUR A1 - Kayler, Zachary E. A1 - Premke, Katrin A1 - Gessler, Arthur A1 - Gessner, Mark O. A1 - Griebler, Christian A1 - Hilt, Sabine A1 - Klemedtsson, Leif A1 - Kuzyakov, Yakov A1 - Reichstein, Markus A1 - Siemens, Jan A1 - Totsche, Kai-Uwe A1 - Tranvik, Lars A1 - Wagner, Annekatrin A1 - Weitere, Markus A1 - Grossart, Hans-Peter T1 - Integrating Aquatic and Terrestrial Perspectives to Improve Insights Into Organic Matter Cycling at the Landscape Scale JF - Frontiers in Earth Science N2 - Across a landscape, aquatic-terrestrial interfaces within and between ecosystems are hotspots of organic matter (OM) mineralization. These interfaces are characterized by sharp spatio-temporal changes in environmental conditions, which affect OM properties and thus control OM mineralization and other transformation processes. Consequently, the extent of OM movement at and across aquatic-terrestrial interfaces is crucial in determining OM turnover and carbon (C) cycling at the landscape scale. Here, we propose expanding current concepts in aquatic and terrestrial ecosystem sciences to comprehensively evaluate OM turnover at the landscape scale. We focus on three main concepts toward explaining OM turnover at the landscape scale: the landscape spatiotemporal context, OM turnover described by priming and ecological stoichiometry, and anthropogenic effects as a disruptor of natural OM transfer magnitudes and pathways. A conceptual framework is introduced that allows for discussing the disparities in spatial and temporal scales of OM transfer, changes in environmental conditions, ecosystem connectivity, and microbial-substrate interactions. The potential relevance of priming effects in both terrestrial and aquatic systems is addressed. For terrestrial systems, we hypothesize that the interplay between the influx of OM, its corresponding elemental composition, and the elemental demand of the microbial communities may alleviate spatial and metabolic thresholds. In comparison, substrate level OM dynamics may be substantially different in aquatic systems due to matrix effects that accentuate the role of abiotic conditions, substrate quality, and microbial community dynamics. We highlight the disproportionate impact anthropogenic activities can have on OM cycling across the landscape. This includes reversing natural OM flows through the landscape, disrupting ecosystem connectivity, and nutrient additions that cascade across the landscape. This knowledge is crucial for a better understanding of OM cycling in a landscape context, in particular since terrestrial and aquatic compartments may respond differently to the ongoing changes in climate, land use, and other anthropogenic interferences. KW - landscape connectivity KW - organic matter mineralization KW - priming effects KW - ecological stoichiometry KW - aquatic-terrestrial interfaces KW - anthropogenic interferences Y1 - 2019 U6 - https://doi.org/10.3389/feart.2019.00127 SN - 2296-6463 VL - 7 PB - Frontiers Research Foundation CY - Lausanne ER - TY - GEN A1 - Mantzouki, Evanthia A1 - Lürling, Miquel A1 - Fastner, Jutta A1 - Domis, Lisette Nicole de Senerpont A1 - Wilk-Woźniak, Elżbieta A1 - Koreiviene, Judita A1 - Seelen, Laura A1 - Teurlincx, Sven A1 - Verstijnen, Yvon A1 - Krztoń, Wojciech A1 - Walusiak, Edward A1 - Karosienė, Jūratė A1 - Kasperovičienė, Jūratė A1 - Savadova, Ksenija A1 - Vitonytė, Irma A1 - Cillero-Castro, Carmen A1 - Budzyńska, Agnieszka A1 - Goldyn, Ryszard A1 - Kozak, Anna A1 - Rosińska, Joanna A1 - Szeląg-Wasielewska, Elżbieta A1 - Domek, Piotr A1 - Jakubowska-Krepska, Natalia A1 - Kwasizur, Kinga A1 - Messyasz, Beata A1 - Pełechata, Aleksandra A1 - Pełechaty, Mariusz A1 - Kokocinski, Mikolaj A1 - García-Murcia, Ana A1 - Real, Monserrat A1 - Romans, Elvira A1 - Noguero-Ribes, Jordi A1 - Duque, David Parreño A1 - Fernández-Morán, Elísabeth A1 - Karakaya, Nusret A1 - Häggqvist, Kerstin A1 - Beklioğlu, Meryem A1 - Filiz, Nur A1 - Levi, Eti E. A1 - Iskin, Uğur A1 - Bezirci, Gizem A1 - Tavşanoğlu, Ülkü Nihan A1 - Özhan, Koray A1 - Gkelis, Spyros A1 - Panou, Manthos A1 - Fakioglu, Özden A1 - Avagianos, Christos A1 - Kaloudis, Triantafyllos A1 - Çelik, Kemal A1 - Yilmaz, Mete A1 - Marcé, Rafael A1 - Catalán, Nuria A1 - Bravo, Andrea G. A1 - Buck, Moritz A1 - Colom-Montero, William A1 - Mustonen, Kristiina A1 - Pierson, Don A1 - Yang, Yang A1 - Raposeiro, Pedro M. A1 - Gonçalves, Vítor A1 - Antoniou, Maria G. A1 - Tsiarta, Nikoletta A1 - McCarthy, Valerie A1 - Perello, Victor C. A1 - Feldmann, Tõnu A1 - Laas, Alo A1 - Panksep, Kristel A1 - Tuvikene, Lea A1 - Gagala, Ilona A1 - Mankiewicz-Boczek, Joana A1 - Yağcı, Meral Apaydın A1 - Çınar, Şakir A1 - Çapkın, Kadir A1 - Yağcı, Abdulkadir A1 - Cesur, Mehmet A1 - Bilgin, Fuat A1 - Bulut, Cafer A1 - Uysal, Rahmi A1 - Obertegger, Ulrike A1 - Boscaini, Adriano A1 - Flaim, Giovanna A1 - Salmaso, Nico A1 - Cerasino, Leonardo A1 - Richardson, Jessica A1 - Visser, Petra M. A1 - Verspagen, Jolanda M. H. A1 - Karan, Tünay A1 - Soylu, Elif Neyran A1 - Maraşlıoğlu, Faruk A1 - Napiórkowska-Krzebietke, Agnieszka A1 - Ochocka, Agnieszka A1 - Pasztaleniec, Agnieszka A1 - Antão-Geraldes, Ana M. A1 - Vasconcelos, Vitor A1 - Morais, João A1 - Vale, Micaela A1 - Köker, Latife A1 - Akçaalan, Reyhan A1 - Albay, Meriç A1 - Maronić, Dubravka Špoljarić A1 - Stević, Filip A1 - Pfeiffer, Tanja Žuna A1 - Fonvielle, Jeremy Andre A1 - Straile, Dietmar A1 - Rothhaupt, Karl-Otto A1 - Hansson, Lars-Anders A1 - Urrutia-Cordero, Pablo A1 - Bláha, Luděk A1 - Geriš, Rodan A1 - Fránková, Markéta A1 - Koçer, Mehmet Ali Turan A1 - Alp, Mehmet Tahir A1 - Remec-Rekar, Spela A1 - Elersek, Tina A1 - Triantis, Theodoros A1 - Zervou, Sevasti-Kiriaki A1 - Hiskia, Anastasia A1 - Haande, Sigrid A1 - Skjelbred, Birger A1 - Madrecka, Beata A1 - Nemova, Hana A1 - Drastichova, Iveta A1 - Chomova, Lucia A1 - Edwards, Christine A1 - Sevindik, Tuğba Ongun A1 - Tunca, Hatice A1 - Önem, Burçin A1 - Aleksovski, Boris A1 - Krstić, Svetislav A1 - Vucelić, Itana Bokan A1 - Nawrocka, Lidia A1 - Salmi, Pauliina A1 - Machado-Vieira, Danielle A1 - Oliveira, Alinne Gurjão De A1 - Delgado-Martín, Jordi A1 - García, David A1 - Cereijo, Jose Luís A1 - Gomà, Joan A1 - Trapote, Mari Carmen A1 - Vegas-Vilarrúbia, Teresa A1 - Obrador, Biel A1 - Grabowska, Magdalena A1 - Karpowicz, Maciej A1 - Chmura, Damian A1 - Úbeda, Bárbara A1 - Gálvez, José Ángel A1 - Özen, Arda A1 - Christoffersen, Kirsten Seestern A1 - Warming, Trine Perlt A1 - Kobos, Justyna A1 - Mazur-Marzec, Hanna A1 - Pérez-Martínez, Carmen A1 - Ramos-Rodríguez, Eloísa A1 - Arvola, Lauri A1 - Alcaraz-Párraga, Pablo A1 - Toporowska, Magdalena A1 - Pawlik-Skowronska, Barbara A1 - Niedźwiecki, Michał A1 - Pęczuła, Wojciech A1 - Leira, Manel A1 - Hernández, Armand A1 - Moreno-Ostos, Enrique A1 - Blanco, José María A1 - Rodríguez, Valeriano A1 - Montes-Pérez, Jorge Juan A1 - Palomino, Roberto L. A1 - Rodríguez-Pérez, Estela A1 - Carballeira, Rafael A1 - Camacho, Antonio A1 - Picazo, Antonio A1 - Rochera, Carlos A1 - Santamans, Anna C. A1 - Ferriol, Carmen A1 - Romo, Susana A1 - Soria, Juan Miguel A1 - Dunalska, Julita A1 - Sieńska, Justyna A1 - Szymański, Daniel A1 - Kruk, Marek A1 - Kostrzewska-Szlakowska, Iwona A1 - Jasser, Iwona A1 - Žutinić, Petar A1 - Udovič, Marija Gligora A1 - Plenković-Moraj, Anđelka A1 - Frąk, Magdalena A1 - Bańkowska-Sobczak, Agnieszka A1 - Wasilewicz, Michał A1 - Özkan, Korhan A1 - Maliaka, Valentini A1 - Kangro, Kersti A1 - Grossart, Hans-Peter A1 - Paerl, Hans W. A1 - Carey, Cayelan C. A1 - Ibelings, Bas W. T1 - Temperature effects explain continental scale distribution of cyanobacterial toxins T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1105 KW - microcystin KW - anatoxin KW - cylindrospermopsin KW - temperature KW - direct effects KW - indirect effects KW - spatial distribution KW - European Multi Lake Survey Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427902 SN - 1866-8372 IS - 1105 ER - TY - GEN A1 - Numberger, Daniela A1 - Dreier, Carola A1 - Vullioud, Colin A1 - Gabriel, Guelsah A1 - Greenwood, Alex D. A1 - Grossart, Hans-Peter T1 - Correction: Recovery of influenza A viruses from lake water and sediments by experimental inoculation (vol 14, e0216880, 2019) T2 - PLoS one Y1 - 2019 U6 - https://doi.org/10.1371/journal.pone.0218882 SN - 1932-6203 VL - 14 IS - 6 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Lundgreen, Regitze B. C. A1 - Jaspers, Cornelia A1 - Traving, Sachia J. A1 - Ayala, Daniel J. A1 - Lombard, Fabien A1 - Grossart, Hans-Peter A1 - Nielsen, Torkel G. A1 - Munk, Peter A1 - Riemann, Lasse T1 - Eukaryotic and cyanobacterial communities associated with marine snow particles in the oligotrophic Sargasso Sea JF - Scientific reports N2 - Marine snow aggregates represent heterogeneous agglomerates of dead and living organic matter. Composition is decisive for their sinking rates, and thereby for carbon flux to the deep sea. For oligotrophic oceans, information on aggregate composition is particularly sparse. To address this, the taxonomic composition of aggregates collected from the subtropical and oligotrophic Sargasso Sea (Atlantic Ocean) was characterized by 16S and 18S rRNA gene sequencing. Taxonomy assignment was aided by a collection of the contemporary plankton community consisting of 75 morphologically and genetically identified plankton specimens. The diverse rRNA gene reads of marine snow aggregates, not considering Trichodesmium puffs, were dominated by copepods (52%), cnidarians (21%), radiolarians (11%), and alveolates (8%), with sporadic contributions by cyanobacteria, suggesting a different aggregate composition than in eutrophic regions. Composition linked significantly with sampling location but not to any measured environmental parameters or plankton biomass composition. Nevertheless, indicator and network analyses identified key roles of a few rare taxa. This points to complex regulation of aggregate composition, conceivably affected by the environment and plankton characteristics. The extent to which this has implications for particle densities, and consequently for sinking rates and carbon sequestration in oligotrophic waters, needs further interrogation. Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-45146-7 SN - 2045-2322 VL - 9 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Tang, Kam W. A1 - Backhaus, Liv A1 - Riemann, Lasse A1 - Koski, Marja A1 - Grossart, Hans-Peter A1 - Munk, Peter A1 - Nielsen, Torkel Gissel T1 - Copepod carcasses in the subtropical convergence zone of the Sargasso Sea BT - implications for microbial community composition, system respiration and carbon flux JF - Journal of plankton research N2 - The oligotrophic subtropical gyre covers a vast area of the Atlantic Ocean. Decades of time-series monitoring have generated detailed temporal information about zooplankton species and abundances at fixed locations within the gyre, but their live/dead status is often omitted, especially in the dynamic subtropical convergence zone (STCZ) where the water column stratification pattern can change considerably across the front as warm and cold water masses converge. We conducted a detailed survey in the North Atlantic STCZ and showed that over 85% of the copepods were typically concentrated in the upper 200 m. Copepod carcasses were present in all samples and their proportional numerical abundances increased with depth, reaching up to 91% at 300-400 m. Overall, 14-19% of the copepods within the upper 200 m were carcasses. Shipboard experiments showed that during carcass decomposition, microbial respiration increased, and the bacterial community associated with the carcasses diverged from that in the ambient water. Combining field and experimental data, we estimated that decomposing copepod carcasses constitute a negligible oxygen sink in the STCZ, but sinking carcasses may represent an overlooked portion of the passive carbon sinking flux and should be incorporated in future studies of carbon flux in this area. KW - Sargasso Sea KW - subtropical convergence zone KW - zooplankton KW - carcasses KW - carbon sinking flux Y1 - 2019 U6 - https://doi.org/10.1093/plankt/fbz038 SN - 0142-7873 SN - 1464-3774 VL - 41 IS - 4 SP - 549 EP - 560 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Numberger, Daniela A1 - Ganzert, Lars A1 - Zoccarato, Luca A1 - Mühldorfer, Kristin A1 - Sauer, Sascha A1 - Grossart, Hans-Peter A1 - Greenwood, Alex D. T1 - Characterization of bacterial communities in wastewater with enhanced taxonomic resolution by full-length 16S rRNA sequencing JF - Scientific reports N2 - Wastewater treatment is crucial to environmental hygiene in urban environments. However, wastewater treatment plants (WWTPs) collect chemicals, organic matter, and microorganisms including pathogens and multi-resistant bacteria from various sources which may be potentially released into the environment via WWTP effluent. To better understand microbial dynamics in WWTPs, we characterized and compared the bacterial community of the inflow and effluent of a WWTP in Berlin, Germany using full-length 16S rRNA gene sequences, which allowed for species level determination in many cases and generally resolved bacterial taxa. Significantly distinct bacterial communities were identified in the wastewater inflow and effluent samples. Dominant operational taxonomic units (OTUs) varied both temporally and spatially. Disease associated bacterial groups were efficiently reduced in their relative abundance from the effluent by the WWTP treatment process, except for Legionella and Leptospira species which demonstrated an increase in relative proportion from inflow to effluent. This indicates that WWTPs, while effective against enteric bacteria, may enrich and release other potentially pathogenic bacteria into the environment. The taxonomic resolution of full-length 16S rRNA genes allows for improved characterization of potential pathogenic taxa and other harmful bacteria which is required to reliably assess health risk. Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-46015-z SN - 2045-2322 VL - 9 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Masigol, Hossein A1 - Khodaparast, Seyed Akbar A1 - Woodhouse, Jason Nicholas A1 - Rojas Jiménez, Keilor A1 - Fonvielle, Jeremy Andre A1 - Rezakhani, Forough A1 - Mostowfizadeh-Ghalamfarsa, Reza A1 - Neubauer, Darshan A1 - Goldhammer, Tobias A1 - Grossart, Hans-Peter T1 - The contrasting roles of aquatic fungi and oomycetes in the degradation and transformation of polymeric organic matter JF - Limnology and oceanography N2 - Studies on the ecological role of fungi and, to a lesser extent, oomycetes, are receiving increasing attention, mainly due to their participation in the cycling of organic matter in aquatic ecosystems. To unravel their importance in humification processes, we isolated several strains of fungi and oomycetes from Anzali lagoon, Iran. We then performed taxonomic characterization by morphological and molecular methods, analyzed the ability to degrade several polymeric substrates, performed metabolic fingerprinting with Ecoplates, and determined the degradation of humic substances (HS) using liquid chromatography-organic carbon detection. Our analyses highlighted the capacity of aquatic fungi to better degrade a plethora of organic molecules, including complex polymers. Specifically, we were able to demonstrate not only the utilization of these complex polymers, but also the role of fungi in the production of HS. In contrast, oomycetes, despite some morphological and physiological similarities with aquatic fungi, exhibited a propensity toward opportunism, quickly benefitting from the availability of small organic molecules, while exhibiting sensitivity toward more complex polymers. Despite their contrasting roles, our study highlights the importance of both oomycetes and fungi in aquatic organic matter transformation and cycling with potential implications for the global carbon cycle. Y1 - 2019 SN - 0024-3590 SN - 1939-5590 VL - 64 IS - 6 SP - 2662 EP - 2678 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Heger, Tina A1 - Bernard-Verdier, Maud A1 - Gessler, Arthur A1 - Greenwood, Alex D. A1 - Grossart, Hans-Peter A1 - Hilker, Monika A1 - Keinath, Silvia A1 - Kowarik, Ingo A1 - Küffer, Christoph A1 - Marquard, Elisabeth A1 - Mueller, Johannes A1 - Niemeier, Stephanie A1 - Onandia, Gabriela A1 - Petermann, Jana S. A1 - Rillig, Matthias C. A1 - Rodel, Mark-Oliver A1 - Saul, Wolf-Christian A1 - Schittko, Conrad A1 - Tockner, Klement A1 - Joshi, Jasmin Radha A1 - Jeschke, Jonathan M. T1 - Towards an Integrative, Eco-Evolutionary Understanding of Ecological Novelty: Studying and Communicating Interlinked Effects of Global Change JF - Bioscience N2 - Global change has complex eco-evolutionary consequences for organisms and ecosystems, but related concepts (e.g., novel ecosystems) do not cover their full range. Here we propose an umbrella concept of "ecological novelty" comprising (1) a site-specific and (2) an organism-centered, eco-evolutionary perspective. Under this umbrella, complementary options for studying and communicating effects of global change on organisms, ecosystems, and landscapes can be included in a toolbox. This allows researchers to address ecological novelty from different perspectives, e.g., by defining it based on (a) categorical or continuous measures, (b) reference conditions related to sites or organisms, and (c) types of human activities. We suggest striving for a descriptive, non-normative usage of the term "ecological novelty" in science. Normative evaluations and decisions about conservation policies or management are important, but require additional societal processes and engagement with multiple stakeholders. KW - Anthropocene KW - eco-evolutionary experience KW - global change KW - novel ecosystems KW - shifting baselines Y1 - 2019 U6 - https://doi.org/10.1093/biosci/biz095 SN - 0006-3568 SN - 1525-3244 VL - 69 IS - 11 SP - 888 EP - 899 PB - Oxford Univ. Press CY - Oxford ER - TY - GEN A1 - Rojas-Jimenez, Keilor A1 - Grossart, Hans-Peter A1 - Cordes, Erik A1 - Cortés, Jorge T1 - Fungal Communities in Sediments Along a Depth Gradient in the Eastern Tropical Pacific T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Deep waters represent the largest biome on Earth and the largest ecosystem of Costa Rica. Fungi play a fundamental role in global biogeochemical cycling in marine sediments, yet, they remain little explored. We studied fungal diversity and community composition in several marine sediments from 16 locations sampled along a bathymetric gradient (from a depth of 380 to 3,474 m) in two transects of about 1,500 km length in the Eastern Tropical Pacific (ETP) of Costa Rica. Sequence analysis of the V7-V8 region of the 18S rRNA gene obtained from sediment cores revealed the presence of 787 fungal amplicon sequence variants (ASVs). On average, we detected a richness of 75 fungal ASVs per sample. Ascomycota represented the most abundant phylum with Saccharomycetes constituting the dominant class. Three ASVs accounted for ca. 63% of all fungal sequences: the yeast Metschnikowia (49.4%), Rhizophydium (6.9%), and Cladosporium (6.7%). We distinguished a cluster composed mainly by yeasts, and a second cluster by filamentous fungi, but we were unable to detect a strong effect of depth and the overlying water temperature, salinity, dissolved oxygen (DO), and pH on the composition of fungal communities. We highlight the need to understand further the ecological role of fungi in deep-sea ecosystems. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1013 KW - deep-sea KW - aquatic fungi KW - biodiversity KW - Metschnikowia KW - Costa Rica Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-482360 SN - 1866-8372 IS - 1013 ER - TY - JOUR A1 - Rojas-Jimenez, Keilor A1 - Grossart, Hans-Peter A1 - Cordes, Erik A1 - Cortés, Jorge T1 - Fungal Communities in Sediments Along a Depth Gradient in the Eastern Tropical Pacific JF - Frontiers in Microbiology N2 - Deep waters represent the largest biome on Earth and the largest ecosystem of Costa Rica. Fungi play a fundamental role in global biogeochemical cycling in marine sediments, yet, they remain little explored. We studied fungal diversity and community composition in several marine sediments from 16 locations sampled along a bathymetric gradient (from a depth of 380 to 3,474 m) in two transects of about 1,500 km length in the Eastern Tropical Pacific (ETP) of Costa Rica. Sequence analysis of the V7-V8 region of the 18S rRNA gene obtained from sediment cores revealed the presence of 787 fungal amplicon sequence variants (ASVs). On average, we detected a richness of 75 fungal ASVs per sample. Ascomycota represented the most abundant phylum with Saccharomycetes constituting the dominant class. Three ASVs accounted for ca. 63% of all fungal sequences: the yeast Metschnikowia (49.4%), Rhizophydium (6.9%), and Cladosporium (6.7%). We distinguished a cluster composed mainly by yeasts, and a second cluster by filamentous fungi, but we were unable to detect a strong effect of depth and the overlying water temperature, salinity, dissolved oxygen (DO), and pH on the composition of fungal communities. We highlight the need to understand further the ecological role of fungi in deep-sea ecosystems. KW - deep-sea KW - aquatic fungi KW - biodiversity KW - Metschnikowia KW - Costa Rica Y1 - 2020 U6 - https://doi.org/10.3389/fmicb.2020.575207 SN - 1664-302X VL - 11 PB - Frontiers Media CY - Lausanne ER - TY - GEN A1 - Srivastava, Abhishek A1 - Murugaiyan, Jayaseelan A1 - Garcia, Juan A. L. A1 - De Corte, Daniele A1 - Hoetzinger, Matthias A1 - Eravci, Murat A1 - Weise, Christoph A1 - Kumar, Yadhu A1 - Roesler, Uwe A1 - Hahn, Martin W. A1 - Grossart, Hans-Peter T1 - Combined Methylome, Transcriptome and Proteome Analyses Document Rapid Acclimatization of a Bacterium to Environmental Changes T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - Polynucleobacter asymbioticus strain QLW-P1DMWA-1T represents a group of highly successful heterotrophic ultramicrobacteria that is frequently very abundant (up to 70% of total bacterioplankton) in freshwater habitats across all seven continents. This strain was originally isolated from a shallow Alpine pond characterized by rapid changes in water temperature and elevated UV radiation due to its location at an altitude of 1300 m. To elucidate the strain’s adjustment to fluctuating environmental conditions, we recorded changes occurring in its transcriptomic and proteomic profiles under contrasting experimental conditions by simulating thermal conditions in winter and summer as well as high UV irradiation. To analyze the potential connection between gene expression and regulation via methyl group modification of the genome, we also analyzed its methylome. The methylation pattern differed between the three treatments, pointing to its potential role in differential gene expression. An adaptive process due to evolutionary pressure in the genus was deduced by calculating the ratios of non-synonymous to synonymous substitution rates for 20 Polynucleobacter spp. genomes obtained from geographically diverse isolates. The results indicate purifying selection. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1011 KW - DNA modification KW - gene expression KW - freshwater heterotrophic bacteria KW - UV radiation KW - purifying selection Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-481993 SN - 1866-8372 IS - 1011 ER - TY - JOUR A1 - Srivastava, Abhishek A1 - Murugaiyan, Jayaseelan A1 - Garcia, Juan A. L. A1 - De Corte, Daniele A1 - Hoetzinger, Matthias A1 - Eravci, Murat A1 - Weise, Christoph A1 - Kumar, Yadhu A1 - Roesler, Uwe A1 - Hahn, Martin W. A1 - Grossart, Hans-Peter T1 - Combined Methylome, Transcriptome and Proteome Analyses Document Rapid Acclimatization of a Bacterium to Environmental Changes JF - Frontiers in Microbiology N2 - Polynucleobacter asymbioticus strain QLW-P1DMWA-1T represents a group of highly successful heterotrophic ultramicrobacteria that is frequently very abundant (up to 70% of total bacterioplankton) in freshwater habitats across all seven continents. This strain was originally isolated from a shallow Alpine pond characterized by rapid changes in water temperature and elevated UV radiation due to its location at an altitude of 1300 m. To elucidate the strain’s adjustment to fluctuating environmental conditions, we recorded changes occurring in its transcriptomic and proteomic profiles under contrasting experimental conditions by simulating thermal conditions in winter and summer as well as high UV irradiation. To analyze the potential connection between gene expression and regulation via methyl group modification of the genome, we also analyzed its methylome. The methylation pattern differed between the three treatments, pointing to its potential role in differential gene expression. An adaptive process due to evolutionary pressure in the genus was deduced by calculating the ratios of non-synonymous to synonymous substitution rates for 20 Polynucleobacter spp. genomes obtained from geographically diverse isolates. The results indicate purifying selection. KW - DNA modification KW - gene expression KW - freshwater heterotrophic bacteria KW - UV radiation KW - purifying selection Y1 - 2020 U6 - https://doi.org/10.3389/fmicb.2020.544785 SN - 1664-302X VL - 11 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Perkins, Anita K. A1 - Ganzert, Lars A1 - Rojas-Jimenez, Keilor A1 - Fonvielle, Jeremy Andre A1 - Hose, Grant C. A1 - Grossart, Hans-Peter T1 - Highly diverse fungal communities in carbon-rich aquifers of two contrasting lakes in Northeast Germany JF - Fungal ecology N2 - Fungi are an important component of microbial communities and are well known for their ability to decompose refractory, highly polymeric organic matter. In soils and aquatic systems, fungi play an important role in carbon processing, however, their diversity, community structure and function as well as ecological role, particularly in groundwater, are poorly studied. The aim of this study was to examine the fungal community composition, diversity and function in groundwater from 16 boreholes located in the vicinity of two lakes in NE Germany that are characterized by contrasting trophic status. The analysis of 28S rRNA gene sequences amplified from the groundwater revealed high fungal diversity arid clear differences in community structure between the aquifers. Most sequences were assigned to Ascomycota and Basidiomycota, but members of Chytridiomycota, Cryptomycota, Zygomycota, Blastocladiomycota, Glomeromycota and Neocallimastigomycota were also detected. In addition, 27 species of fungi were successfully isolated from the groundwater samples and tested for their ability to decompose complex organic polymers - the predominant carbon source in the groundwater. Most isolates showed positive activities for at least one of the tested polymer types, with three strains, belonging to the genera Gibberella, Isaria and Cadophora, able to decompose all tested substrates. Our results highlight the high diversity of fungi in groundwater, and point to their important ecological role in breaking down highly polymeric organic matter in these isolated microbial habitats. (C) 2019 Elsevier Ltd and British Mycological Society. All rights reserved. KW - Groundwater KW - Aquatic fungi KW - DOC KW - CDOM KW - Aquifers KW - Humic acids Y1 - 2019 U6 - https://doi.org/10.1016/j.funeco.2019.04.004 SN - 1754-5048 SN - 1878-0083 VL - 41 SP - 116 EP - 125 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Günthel, Marco A1 - Donis, Daphne A1 - Kirillin, Georgiy A1 - Ionescu, Danny A1 - Bizic, Mina A1 - McGinnis, Daniel F. A1 - Grossart, Hans-Peter A1 - Tang, Kam W. T1 - Contribution of oxic methane production to surface methane emission in lakes and its global importance JF - Nature Communications N2 - Recent discovery of oxic methane production in sea and lake waters, as well as wetlands, demands re-thinking of the global methane cycle and re-assessment of the contribution of oxic waters to atmospheric methane emission. Here we analysed system-wide sources and sinks of surface-water methane in a temperate lake. Using a mass balance analysis, we show that internal methane production in well-oxygenated surface water is an important source for surface-water methane during the stratified period. Combining our results and literature reports, oxic methane contribution to emission follows a predictive function of littoral sediment area and surface mixed layer volume. The contribution of oxic methane source(s) is predicted to increase with lake size, accounting for the majority (>50%) of surface methane emission for lakes with surface areas >1 km(2). Y1 - 2019 U6 - https://doi.org/10.1038/s41467-019-13320-0 SN - 2041-1723 VL - 10 PB - Nature Publishing Group UK CY - London ER - TY - GEN A1 - Gubelit, Yulia I. A1 - Grossart, Hans-Peter T1 - New Methods, New Concepts BT - What Can Be Applied to Freshwater Periphyton? T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Microbial interactions play an essential role in aquatic ecosystems and are of the great interest for both marine and freshwater ecologists. Recent development of new technologies and methods allowed to reveal many functional mechanisms and create new concepts. Yet, many fundamental aspects of microbial interactions have been almost exclusively studied for marine pelagic and benthic ecosystems. These studies resulted in a formulation of the Black Queen Hypothesis, a development of the phycosphere concept for pelagic communities, and a realization of microbial communication as a key mechanism for microbial interactions. In freshwater ecosystems, especially for periphyton communities, studies focus mainly on physiology, biodiversity, biological indication, and assessment, but the many aspects of microbial interactions are neglected to a large extent. Since periphyton plays a great role for aquatic nutrient cycling, provides the basis for water purification, and can be regarded as a hotspot of microbial biodiversity, we highlight that more in-depth studies on microbial interactions in periphyton are needed to improve our understanding on functioning of freshwater ecosystems. In this paper we first present an overview on recent concepts (e.g., the “Black Queen Hypothesis”) derived from state-of-the-art OMICS methods including metagenomics, metatranscriptomics, and metabolomics. We then point to the avenues how these methods can be applied for future studies on biodiversity and the ecological role of freshwater periphyton, a yet largely neglected component of many freshwater ecosystems. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 969 KW - freshwater KW - lake periphyton KW - microbial interactions KW - Black Queen Hypothesis KW - OMICs tools Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-474286 SN - 1866-8372 IS - 969 ER - TY - JOUR A1 - Gubelit, Yulia I. A1 - Grossart, Hans-Peter T1 - New Methods, New Concepts BT - What Can Be Applied to Freshwater Periphyton? JF - Frontiers in Microbiology N2 - Microbial interactions play an essential role in aquatic ecosystems and are of the great interest for both marine and freshwater ecologists. Recent development of new technologies and methods allowed to reveal many functional mechanisms and create new concepts. Yet, many fundamental aspects of microbial interactions have been almost exclusively studied for marine pelagic and benthic ecosystems. These studies resulted in a formulation of the Black Queen Hypothesis, a development of the phycosphere concept for pelagic communities, and a realization of microbial communication as a key mechanism for microbial interactions. In freshwater ecosystems, especially for periphyton communities, studies focus mainly on physiology, biodiversity, biological indication, and assessment, but the many aspects of microbial interactions are neglected to a large extent. Since periphyton plays a great role for aquatic nutrient cycling, provides the basis for water purification, and can be regarded as a hotspot of microbial biodiversity, we highlight that more in-depth studies on microbial interactions in periphyton are needed to improve our understanding on functioning of freshwater ecosystems. In this paper we first present an overview on recent concepts (e.g., the “Black Queen Hypothesis”) derived from state-of-the-art OMICS methods including metagenomics, metatranscriptomics, and metabolomics. We then point to the avenues how these methods can be applied for future studies on biodiversity and the ecological role of freshwater periphyton, a yet largely neglected component of many freshwater ecosystems. KW - freshwater KW - lake periphyton KW - microbial interactions KW - Black Queen Hypothesis KW - OMICs tools Y1 - 2020 U6 - https://doi.org/10.3389/fmicb.2020.01275 SN - 1664-302X VL - 11 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Giling, Darren P. A1 - Nejstgaard, Jens C. A1 - Berger, Stella A. A1 - Grossart, Hans-Peter A1 - Kirillin, Georgiy A1 - Penske, Armin A1 - Lentz, Maren A1 - Casper, Peter A1 - Sareyka, Joerg A1 - Gessner, Mark O. T1 - Thermocline deepening boosts ecosystem metabolism: evidence from a large-scale lake enclosure experiment simulating a summer storm JF - Global change biology N2 - Extreme weather events can pervasively influence ecosystems. Observations in lakes indicate that severe storms in particular can have pronounced ecosystem-scale consequences, but the underlying mechanisms have not been rigorously assessed in experiments. One major effect of storms on lakes is the redistribution of mineral resources and plankton communities as a result of abrupt thermocline deepening. We aimed at elucidating the importance of this effect by mimicking in replicated large enclosures (each 9 m in diameter, ca. 20 m deep, ca. 1300 m 3 in volume) a mixing event caused by a severe natural storm that was previously observed in a deep clear-water lake. Metabolic rates were derived from diel changes in vertical profiles of dissolved oxygen concentrations using a Bayesian modelling approach, based on high-frequency measurements. Experimental thermocline deepening stimulated daily gross primary production (GPP) in surface waters by an average of 63% for > 4 weeks even though thermal stratification re-established within 5 days. Ecosystem respiration (ER) was tightly coupled to GPP, exceeding that in control enclosures by 53% over the same period. As GPP responded more strongly than ER, net ecosystem productivity (NEP) of the entire water column was also increased. These protracted increases in ecosystem metabolism and autotrophy were driven by a proliferation of inedible filamentous cyanobacteria released from light and nutrient limitation after they were entrained from below the thermocline into the surface water. Thus, thermocline deepening by a single severe storm can induce prolonged responses of lake ecosystem metabolism independent of other storm-induced effects, such as inputs of terrestrial materials by increased catchment run-off. This highlights that future shifts in frequency, severity or timing of storms are an important component of climate change, whose impacts on lake thermal structure will superimpose upon climate trends to influence algal dynamics and organic matter cycling in clear-water lakes. Keywords: climate variability, ecosystem productivity, extreme events, gross primary production, mesocosm, respiration stratified lakes KW - climate variability KW - ecosystem productivity KW - extreme events KW - gross primary production KW - mesocosm KW - respiration stratified lakes Y1 - 2017 U6 - https://doi.org/10.1111/gcb.13512 SN - 1354-1013 SN - 1365-2486 VL - 23 SP - 1448 EP - 1462 PB - Wiley CY - Hoboken ER - TY - GEN A1 - Kalinkat, Gregor A1 - Cabral, Juliano Sarmento A1 - Darwall, William A1 - Ficetola, G. Francesco A1 - Fisher, Judith L. A1 - Giling, Darren P. A1 - Gosselin, Marie-Pierre A1 - Grossart, Hans-Peter A1 - Jaehnig, Sonja C. A1 - Jeschke, Jonathan M. A1 - Knopf, Klaus A1 - Larsen, Stefano A1 - Onandia, Gabriela A1 - Paetzig, Marlene A1 - Saul, Wolf-Christian A1 - Singer, Gabriel A1 - Sperfeld, Erik A1 - Jaric, Ivan T1 - Flagship umbrella species needed for the conservation of overlooked aquatic biodiversity T2 - Conservation biology : the journal of the Society for Conservation Biology Y1 - 2017 U6 - https://doi.org/10.1111/cobi.12813 SN - 0888-8892 SN - 1523-1739 VL - 31 SP - 481 EP - 485 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Giling, Darren P. A1 - Staehr, Peter A. A1 - Grossart, Hans-Peter A1 - Andersen, Mikkel Rene A1 - Boehrer, Bertram A1 - Escot, Carmelo A1 - Evrendilek, Fatih A1 - Gomez-Gener, Lluis A1 - Honti, Mark A1 - Jones, Ian D. A1 - Karakaya, Nusret A1 - Laas, Alo A1 - Moreno-Ostos, Enrique A1 - Rinke, Karsten A1 - Scharfenberger, Ulrike A1 - Schmidt, Silke R. A1 - Weber, Michael A1 - Woolway, R. Iestyn A1 - Zwart, Jacob A. A1 - Obrador, Biel T1 - Delving deeper: Metabolic processes in the metalimnion of stratified lakes JF - Limnology and oceanography N2 - Many lakes exhibit seasonal stratification, during which they develop strong thermal and chemical gradients. An expansion of depth-integrated monitoring programs has provided insight into the importance of organic carbon processing that occurs below the upper mixed layer. However, the chemical and physical drivers of metabolism and metabolic coupling remain unresolved, especially in the metalimnion. In this depth zone, sharp gradients in key resources such as light and temperature co-occur with dynamic physical conditions that influence metabolic processes directly and simultaneously hamper the accurate tracing of biological activity. We evaluated the drivers of metalimnetic metabolism and its associated uncertainty across 10 stratified lakes in Europe and North America. We hypothesized that the metalimnion would contribute highly to whole-lake functioning in clear oligotrophic lakes, and that metabolic rates would be highly variable in unstable polymictic lakes. Depth-integrated rates of gross primary production (GPP) and ecosystem respiration (ER) were modelled from diel dissolved oxygen curves using a Bayesian approach. Metabolic estimates were more uncertain below the epilimnion, but uncertainty was not consistently related to lake morphology or mixing regime. Metalimnetic rates exhibited high day-to-day variability in all trophic states, with the metalimnetic contribution to daily whole-lake GPP and ER ranging from 0% to 87% and < 1% to 92%, respectively. Nonetheless, the metalimnion of low-nutrient lakes contributed strongly to whole-lake metabolism on average, driven by a collinear combination of highlight, low surface-water phosphorous concentration and high metalimnetic volume. Consequently, a single-sensor approach does not necessarily reflect whole-ecosystem carbon dynamics in stratified lakes. Y1 - 2017 U6 - https://doi.org/10.1002/lno.10504 SN - 0024-3590 SN - 1939-5590 VL - 62 SP - 1288 EP - 1306 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Lau, Maximilian P. A1 - Hupfer, Michael A1 - Grossart, Hans-Peter T1 - Reduction-oxidation cycles of organic matter increase bacterial activity in the pelagic oxycline JF - Environmental microbiology reports N2 - Dissolved organic matter (DOM) in aquatic ecosystems contains redox-active moieties, which are prone to oxidation and reduction reactions. Oxidized moieties feature reduction potentials E-h, so that the moieties may be used as terminal electron acceptors (TEAs) in microbial respiration with a thermodynamic energy yield between nitrate and sulfate reduction. Here, we study the response of pelagic freshwater bacteria to exposure to native DOM with varying availabilities of oxidized moieties and hence redox state. Our results show that the prevalence of oxidized DOM favors microbial production and growth in anoxic waters. Reduced DOM in stratified lakes may be oxidized when fluctuations of the oxycline expose DOM in previously anoxic water to epilimnetic oxygen. The resulting oxidized DOM may be rapidly used as TEAs in microbial respiration during subsequent periods of anoxia. We further investigate if the prevalence of these organic electron sinks in anaerobic incubations can induce changes in the microbial community. Our results reveal that DOM traversing transient redox interfaces selects for species that profit from such spatially confined and cyclically restored TEA reservoirs. Y1 - 2017 U6 - https://doi.org/10.1111/1758-2229.12526 SN - 1758-2229 VL - 9 SP - 257 EP - 267 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Attermeyer, Katrin A1 - Grossart, Hans-Peter A1 - Flury, Sabine A1 - Premke, Katrin T1 - Bacterial processes and biogeochemical changes in the water body of kettle holes - mainly driven by autochthonous organic matter? JF - Aquatic sciences : research across boundaries N2 - Kettle holes are small inland waters formed from glacially-created depressions often situated in agricultural landscapes. Due to their high perimeter-to-area ratio facilitating a high aquatic-terrestrial coupling, kettle holes can accumulate high concentrations of organic carbon and nutrients, fueling microbial activities and turnover rates. Thus, they represent hotspots of carbon turnover in the landscape, but their bacterial activities and controlling factors have not been well investigated. Therefore, we aimed to assess the relative importance of various environmental factors on bacterial and biogeochemical processes in the water column of kettle holes and to disentangle their variations. In the water body of ten kettle holes in north-eastern Germany, we measured several physico-chemical and biological parameters such as carbon quantity and quality, as well as bacterial protein production (BP) and community respiration (CR) in spring, early summer and autumn 2014. Particulate organic matter served as an indicator of autochthonous production and represented an important parameter to explain variations in BP and CR. This notion is supported by qualitative absorbance indices of dissolved molecules in water samples and C: N ratios of the sediments, which demonstrate high fractions of autochthonous organic matter (OM) in the studied kettle holes. In contrast, dissolved chemical parameters were less important for bacterial activities although they revealed strong differences throughout the growing season. Pelagic bacterial activities and dynamics might thus be regulated by autochthonous OM in kettle holes implying a control of important biogeochemical processes by internal primary production rather than facilitated exchange with the terrestrial surrounding due to a high perimeter-to-area ratio. KW - Bacterial production KW - Carbon turnover KW - Growth efficiency KW - Ponds KW - Respiration KW - DOC quality KW - LC-OCD Y1 - 2017 U6 - https://doi.org/10.1007/s00027-017-0528-1 SN - 1015-1621 SN - 1420-9055 VL - 79 SP - 675 EP - 687 PB - Springer CY - Basel ER - TY - JOUR A1 - Wurzbacher, Christian A1 - Attermeyer, Katrin A1 - Kettner, Marie Therese A1 - Flintrop, Clara A1 - Warthmann, Norman A1 - Hilt, Sabine A1 - Grossart, Hans-Peter A1 - Monaghan, Michael T. T1 - DNA metabarcoding of unfractionated water samples relates phyto-, zoo- and bacterioplankton dynamics and reveals a single-taxon bacterial bloom JF - Environmental microbiology reports N2 - Most studies of aquatic plankton focus on either macroscopic or microbial communities, and on either eukaryotes or prokaryotes. This separation is primarily for methodological reasons, but can overlook potential interactions among groups. Here we tested whether DNA metabarcoding of unfractionated water samples with universal primers could be used to qualitatively and quantitatively study the temporal dynamics of the total plankton community in a shallow temperate lake. Significant changes in the relative proportions of normalized sequence reads of eukaryotic and prokaryotic plankton communities over a 3-month period in spring were found. Patterns followed the same trend as plankton estimates measured using traditional microscopic methods. The bloom of a conditionally rare bacterial taxon belonging to Arcicella was characterized, which rapidly came to dominate the whole lake ecosystem and would have remained unnoticed without metabarcoding. The data demonstrate the potential of universal DNA metabarcoding applied to unfractionated samples for providing a more holistic view of plankton communities. Y1 - 2017 U6 - https://doi.org/10.1111/1758-2229.12540 SN - 1758-2229 VL - 9 SP - 383 EP - 388 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Ionescu, Danny A1 - Bizic-Ionescu, Mina A1 - De Maio, Nicola A1 - Cypionka, Heribert A1 - Grossart, Hans-Peter T1 - Community-like genome in single cells of the sulfur bacterium Achromatium oxaliferum JF - Nature Communications Y1 - 2017 U6 - https://doi.org/10.1038/s41467-017-00342-9 SN - 2041-1723 VL - 8 SP - 9193 EP - 9205 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Amalfitano, Stefano A1 - Corno, Gianluca A1 - Eckert, Ester A1 - Fazi, Stefano A1 - Ninio, Shira A1 - Callieri, Cristiana A1 - Grossart, Hans-Peter A1 - Eckert, Werner T1 - Tracing particulate matter and associated microorganisms in freshwaters JF - Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica N2 - Sediment resuspension represents a key process in all natural aquatic systems, owing to its role in nutrient cycling and transport of potential contaminants. Although suspended solids are generally accepted as an important quality parameter, current monitoring programs cover quantitative aspects only. Established methodologies do not provide information on origin, fate, and risks associated with uncontrolled inputs of solids in waters. Here we discuss the analytical approaches to assess the occurrence and ecological relevance of resuspended particulate matter in freshwaters, with a focus on the dynamics of associated contaminants and microorganisms. Triggered by the identification of specific physical-chemical traits and community structure of particle-associated microorganisms, recent findings suggest that a quantitative determination of microorganisms can be reasonably used to trace the origin of particulate matter by means of nucleic acid-based assays in different aquatic systems. KW - Total suspended solids KW - Resuspended particulate KW - Turbidity KW - Sediment traps KW - Particle-associated microorganisms KW - Pathogens Y1 - 2017 U6 - https://doi.org/10.1007/s10750-017-3260-x SN - 0018-8158 SN - 1573-5117 VL - 800 SP - 145 EP - 154 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Tang, Kam W. A1 - Flury, Sabine A1 - Grossart, Hans-Peter A1 - McGinnis, Daniel F. T1 - The Chaoborus pump: Migrating phantom midge larvae sustain hypolimnetic oxygen deficiency and nutrient internal loading in lakes JF - Water research N2 - Hypolimnetic oxygen demand in lakes is often assumed to be driven mainly by sediment microbial processes, while the role of Chaoborus larvae, which are prevalent in eutrophic lakes with hypoxic to anoxic bottoms, has been overlooked. We experimentally measured the respiration rates of C flavicans at different temperatures yielding a Q(10) of 1.44-1.71 and a respiratory quotient of 0.84-0.98. Applying the experimental data in a system analytical approach, we showed that migrating Chaoborus larvae can significantly add to the water column and sediment oxygen demand, and contribute to the observed linear relationship between water column respiration and depth. The estimated phosphorus excretion by Chaoborus in sediment is comparable in magnitude to the required phosphorus loading for eutrophication. Migrating Chaoborus larvae thereby essentially trap nutrients between the water column and the sediment, and this continuous internal loading of nutrients would delay lake remediation even when external inputs are stopped. (C) 2017 Elsevier Ltd. All rights reserved. KW - Chaoborus KW - Eutrophication KW - Oxygen KW - Nutrient KW - Remediation Y1 - 2017 U6 - https://doi.org/10.1016/j.watres.2017.05.058 SN - 0043-1354 VL - 122 SP - 36 EP - 41 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Lischke, Betty A1 - Mehner, Thomas A1 - Hilt, Sabine A1 - Attermeyer, Katrin A1 - Brauns, Mario A1 - Brothers, Soren M. A1 - Grossart, Hans-Peter A1 - Koehler, Jan A1 - Scharnweber, Inga Kristin A1 - Gaedke, Ursula T1 - Benthic carbon is inefficiently transferred in the food webs of two eutrophic shallow lakes JF - Freshwater biology N2 - The sum of benthic autotrophic and bacterial production often exceeds the sum of pelagic autotrophic and bacterial production, and hence may contribute substantially to whole-lake carbon fluxes, especially in shallow lakes. Furthermore, both benthic and pelagic autotrophic and bacterial production are highly edible and of sufficient nutritional quality for animal consumers. We thus hypothesised that pelagic and benthic transfer efficiencies (ratios of production at adjacent trophic levels) in shallow lakes should be similar. We performed whole ecosystem studies in two shallow lakes (3.5ha, mean depth 2m), one with and one without submerged macrophytes, and quantified pelagic and benthic biomass, production and transfer efficiencies for bacteria, phytoplankton, epipelon, epiphyton, macrophytes, zooplankton, macrozoobenthos and fish. We expected higher transfer efficiencies in the lake with macrophytes, because these provide shelter and food for macrozoobenthos and may thus enable a more efficient conversion of basal production to consumer production. In both lakes, the majority of the whole-lake autotrophic and bacterial production was provided by benthic organisms, but whole-lake primary consumer production mostly relied on pelagic autotrophic and bacterial production. Consequently, transfer efficiency of benthic autotrophic and bacterial production to macrozoobenthos production was an order of magnitude lower than the transfer efficiency of pelagic autotrophic and bacterial production to rotifer and crustacean production. Between-lake differences in transfer efficiencies were minor. We discuss several aspects potentially causing the unexpectedly low benthic transfer efficiencies, such as the food quality of producers, pelagic-benthic links, oxygen concentrations in the deeper lake areas and additional unaccounted consumer production by pelagic and benthic protozoa and meiobenthos at intermediate or top trophic levels. None of these processes convincingly explain the large differences between benthic and pelagic transfer efficiencies. Our data indicate that shallow eutrophic lakes, even with a major share of autotrophic and bacterial production in the benthic zone, can function as pelagic systems with respect to primary consumer production. We suggest that the benthic autotrophic production was mostly transferred to benthic bacterial production, which remained in the sediments, potentially cycling internally in a similar way to what has previously been described for the microbial loop in pelagic habitats. Understanding the energetics of whole-lake food webs, including the fate of the substantial benthic bacterial production, which is either mineralised at the sediment surface or permanently buried, has important implications for regional and global carbon cycling. KW - bacterial production KW - benthic food chain KW - pelagic food chain KW - quantitative food webs KW - trophic transfer efficiency Y1 - 2017 U6 - https://doi.org/10.1111/fwb.12979 SN - 0046-5070 SN - 1365-2427 VL - 62 SP - 1693 EP - 1706 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Rojas-Jimenez, Keilor A1 - Wurzbacher, Christian A1 - Bourne, Elizabeth Charlotte A1 - Chiuchiolo, Amy A1 - Priscu, John C. A1 - Grossart, Hans-Peter T1 - Early diverging lineages within Cryptomycota and Chytridiomycota dominate the fungal communities in ice-covered lakes of the McMurdo Dry Valleys, Antarctica JF - Scientific reports N2 - Antarctic ice-covered lakes are exceptional sites for studying the ecology of aquatic fungi under conditions of minimal human disturbance. In this study, we explored the diversity and community composition of fungi in five permanently covered lake basins located in the Taylor and Miers Valleys of Antarctica. Based on analysis of the 18S rRNA sequences, we showed that fungal taxa represented between 0.93% and 60.32% of the eukaryotic sequences. Cryptomycota and Chytridiomycota dominated the fungal communities in all lakes; however, members of Ascomycota, Basidiomycota, Zygomycota, and Blastocladiomycota were also present. Of the 1313 fungal OTUs identified, the two most abundant, belonging to LKM11 and Chytridiaceae, comprised 74% of the sequences. Significant differences in the community structure were determined among lakes, water depths, habitat features (i.e., brackish vs. freshwaters), and nucleic acids (DNA vs. RNA), suggesting niche differentiation. Network analysis suggested the existence of strong relationships among specific fungal phylotypes as well as between fungi and other eukaryotes. This study sheds light on the biology and ecology of basal fungi in aquatic systems. To our knowledge, this is the first report showing the predominance of early diverging lineages of fungi in pristine limnetic ecosystems, particularly of the enigmatic phylum Cryptomycota. Y1 - 2017 U6 - https://doi.org/10.1038/s41598-017-15598-w SN - 2045-2322 VL - 7 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Mestre, Mireia A1 - Ferrera, Isabel A1 - Borrull, Encarna A1 - Ortega-Retuerta, Eva A1 - Mbedi, Susan A1 - Grossart, Hans-Peter A1 - Gasol, Josep M. A1 - Sala, M. Montserrat T1 - Spatial variability of marine bacterial and archaeal communities along the particulate matter continuum JF - Molecular ecology N2 - Biotic and abiotic particles shape the microspatial architecture that defines the microbial aquatic habitat, being particles highly variable in size and quality along oceanic horizontal and vertical gradients. We analysed the prokaryotic (bacterial and archaeal) diversity and community composition present in six distinct particle size classes ranging from the pico-to the microscale (0.2 to 200 lm). Further, we studied their variations along oceanographic horizontal (from the coast to open oceanic waters) and vertical (from the ocean surface into the meso-and bathypelagic ocean) gradients. In general, prokaryotic community composition was more variable with depth than in the transition from the coast to the open ocean. Comparing the six size-fractions, distinct prokaryotic communities were detected in each size-fraction, and whereas bacteria were more diverse in the larger size-fractions, archaea were more diverse in the smaller size-fractions. Comparison of prokaryotic community composition among particle size-fractions showed that most, but not all, taxonomic groups have a preference for a certain size-fraction sustained with depth. Species sorting, or the presence of diverse ecotypes with distinct size-fraction preferences, may explain why this trend is not conserved in all taxa. KW - attached KW - free-living KW - particulate matter KW - prokaryotic community KW - spatial variability Y1 - 2017 U6 - https://doi.org/10.1111/mec.14421 SN - 0962-1083 SN - 1365-294X VL - 26 SP - 6827 EP - 6840 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Mehner, T. A1 - Attermeyer, Katrin A1 - Brauns, Mario A1 - Brothers, Soren M. A1 - Diekmann, J. A1 - Gaedke, Ursula A1 - Grossart, Hans-Peter A1 - Koehler, J. A1 - Lischke, Betty A1 - Meyer, N. A1 - Scharnweber, Inga Kristin A1 - Syvaranta, J. A1 - Vanni, M. J. A1 - Hilt, S. T1 - Weak Response of Animal Allochthony and Production to Enhanced Supply of Terrestrial Leaf Litter in Nutrient-Rich Lakes JF - Ecosystems N2 - Ecosystems are generally linked via fluxes of nutrients and energy across their boundaries. For example, freshwater ecosystems in temperate regions may receive significant inputs of terrestrially derived carbon via autumnal leaf litter. This terrestrial particulate organic carbon (POC) is hypothesized to subsidize animal production in lakes, but direct evidence is still lacking. We divided two small eutrophic lakes each into two sections and added isotopically distinct maize litter to the treatment sections to simulate increased terrestrial POC inputs via leaf litter in autumn. We quantified the reliance of aquatic consumers on terrestrial resources (allochthony) in the year subsequent to POC additions by applying mixing models of stable isotopes. We also estimated lake-wide carbon (C) balances to calculate the C flow to the production of the major aquatic consumer groups: benthic macroinvertebrates, crustacean zooplankton, and fish. The sum of secondary production of crustaceans and benthic macroinvertebrates supported by terrestrial POC was higher in the treatment sections of both lakes. In contrast, total secondary and tertiary production (supported by both autochthonous and allochthonous C) was higher in the reference than in the treatment sections of both lakes. Average aquatic consumer allochthony per lake section was 27-40%, although terrestrial POC contributed less than about 10% to total organic C supply to the lakes. The production of aquatic consumers incorporated less than 5% of the total organic C supply in both lakes, indicating a low ecological efficiency. We suggest that the consumption of terrestrial POC by aquatic consumers facilitates a strong coupling with the terrestrial environment. However, the high autochthonous production and the large pool of autochthonous detritus in these nutrient-rich lakes make terrestrial POC quantitatively unimportant for the C flows within food webs. KW - stable isotopes KW - terrestrial subsidy KW - carbon budget KW - ecological efficiency KW - benthic food web KW - pelagic food web Y1 - 2016 U6 - https://doi.org/10.1007/s10021-015-9933-2 SN - 1432-9840 SN - 1435-0629 VL - 19 SP - 311 EP - 325 PB - Springer CY - New York ER - TY - JOUR A1 - Izhitskiy, A. S. A1 - Zavialov, P. O. A1 - Sapozhnikov, P. V. A1 - Kirillin, G. B. A1 - Grossart, Hans-Peter A1 - Kalinina, O. Y. A1 - Zalota, A. K. A1 - Goncharenko, I. V. A1 - Kurbaniyazov, A. K. T1 - Present state of the Aral Sea: diverging physical and biological characteristics of the residual basins JF - Scientific reports N2 - Latest data on the hydrophysical and biological state of the residual basins of the Aral Sea are presented and compared. Direct, quasi-simultaneous observations were carried out in the central part of the Western Large Aral Sea, the northern extremity of the Large Aral known as Chernyshev Bay, Lake Tshchebas, and the Small Aral Sea in October 2014. The Large Aral Sea and Lake Tshchebas transformed into hyperhaline water bodies with highly special taxocene structure. The Small Aral Sea was a relatively diverse brackish ecosystem, which was rather similar to the pre-desiccation environment. The Small Aral Sea and Lake Tshchebas exhibited a fully-mixed vertical structure, whereas the Western Large Aral Sea was strongly stratified. Our data show that during desiccation, different parts of the Aral Sea experienced different environmental conditions, resulting in qualitative and quantitative differences in the physical and biological regimes among the different residual basins. Y1 - 2016 U6 - https://doi.org/10.1038/srep23906 SN - 2045-2322 VL - 6 SP - 1435 EP - 1442 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Adel, Mustafa A1 - Elbehery, Ali H. A. A1 - Aziz, Sherry K. A1 - Aziz, Ramy K. A1 - Grossart, Hans-Peter A1 - Siam, Rania T1 - Viruses-to-mobile genetic elements skew in the deep Atlantis II brine pool sediments JF - Scientific reports N2 - The central rift of the Red Sea has 25 brine pools with different physical and geochemical characteristics. Atlantis II (ATIID), Discovery Deeps (DD) and Chain Deep (CD) are characterized by high salinity, temperature and metal content. Several studies reported microbial communities in these brine pools, but few studies addressed the brine pool sediments. Therefore, sediment cores were collected from ATIID, DD, CD brine pools and an adjacent brine-influenced site. Sixteen different lithologic sediment sections were subjected to shotgun DNA pyrosequencing to generate 1.47 billion base pairs (1.47 x 10(9) bp). We generated sediment-specific reads and attempted to annotate all reads. We report the phylogenetic and biochemical uniqueness of the deepest ATIID sulfur-rich brine pool sediments. In contrary to all other sediment sections, bacteria dominate the deepest ATIID sulfur-rich brine pool sediments. This decrease in virus-to-bacteria ratio in selected sections and depth coincided with an overrepresentation of mobile genetic elements. Skewing in the composition of viruses-to-mobile genetic elements may uniquely contribute to the distinct microbial consortium in sediments in proximity to hydrothermally active vents of the Red Sea and possibly in their surroundings, through differential horizontal gene transfer. Y1 - 2016 U6 - https://doi.org/10.1038/srep32704 SN - 2045-2322 VL - 6 SP - 8882 EP - 8888 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Marce, Rafael A1 - George, Glen A1 - Buscarinu, Paola A1 - Deidda, Melania A1 - Dunalska, Julita A1 - de Eyto, Elvira A1 - Flaim, Giovanna A1 - Grossart, Hans-Peter A1 - Istvanovics, Vera A1 - Lenhardt, Mirjana A1 - Moreno-Ostos, Enrique A1 - Obrador, Biel A1 - Ostrovsky, Ilia A1 - Pierson, Donald C. A1 - Potuzak, Jan A1 - Poikane, Sandra A1 - Rinke, Karsten A1 - Rodriguez-Mozaz, Sara A1 - Staehr, Peter A. A1 - Sumberova, Katerina A1 - Waajen, Guido A1 - Weyhenmeyer, Gesa A. A1 - Weathers, Kathleen C. A1 - Zion, Mark A1 - Ibelings, Bas W. A1 - Jennings, Eleanor T1 - Automatic High Frequency Monitoring for Improved Lake and Reservoir Management JF - Frontiers in plant science N2 - Recent technological developments have increased the number of variables being monitored in lakes and reservoirs using automatic high frequency monitoring (AHFM). However, design of AHFM systems and posterior data handling and interpretation are currently being developed on a site-by-site and issue-by-issue basis with minimal standardization of protocols or knowledge sharing. As a result, many deployments become short-lived or underutilized, and many new scientific developments that are potentially useful for water management and environmental legislation remain underexplored. This Critical Review bridges scientific uses of AHFM with their applications by providing an overview of the current AHFM capabilities, together with examples of successful applications. We review the use of AHFM for maximizing the provision of ecosystem services supplied, by lakes and reservoirs (consumptive and non consumptive uses, food production, and recreation), and for reporting lake status in the EU Water Framework Directive. We also highlight critical issues to enhance the application of AHFM, and suggest the establishment of appropriate networks to facilitate knowledge sharing and technological transfer between potential users. Finally, we give advice on how modern sensor technology can successfully be applied on a larger scale to the management of lakes and reservoirs and maximize the ecosystem services they provide. Y1 - 2016 U6 - https://doi.org/10.1021/acs.est.6b01604 SN - 0013-936X SN - 1520-5851 VL - 50 SP - 10780 EP - 10794 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Spilling, Kristian A1 - Schulz, Kai G. A1 - Paul, Allanah J. A1 - Boxhammer, Tim A1 - Achterberg, Eric Pieter A1 - Hornick, Thomas A1 - Lischka, Silke A1 - Stuhr, Annegret A1 - Bermudez, Rafael A1 - Czerny, Jan A1 - Crawfurd, Kate A1 - Brussaard, Corina P. D. A1 - Grossart, Hans-Peter A1 - Riebesell, Ulf T1 - Effects of ocean acidification on pelagic carbon fluxes in a mesocosm experiment JF - Biogeosciences N2 - About a quarter of anthropogenic CO2 emissions are currently taken up by the oceans, decreasing seawater pH. We performed a mesocosm experiment in the Baltic Sea in order to investigate the consequences of increasing CO2 levels on pelagic carbon fluxes. A gradient of different CO2 scenarios, ranging from ambient (similar to 370 mu atm) to high (similar to 1200 mu atm), were set up in mesocosm bags (similar to 55m(3)). We determined standing stocks and temporal changes of total particulate carbon (TPC), dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and particulate organic carbon (POC) of specific plankton groups. We also measured carbon flux via CO2 exchange with the atmosphere and sedimentation (export), and biological rate measurements of primary production, bacterial production, and total respiration. The experiment lasted for 44 days and was divided into three different phases (I: t0-t16; II: t17-t30; III: t31-t43). Pools of TPC, DOC, and DIC were approximately 420, 7200, and 25 200 mmol Cm-2 at the start of the experiment, and the initial CO2 additions increased the DIC pool by similar to 7% in the highest CO2 treatment. Overall, there was a decrease in TPC and increase of DOC over the course of the experiment. The decrease in TPC was lower, and increase in DOC higher, in treatments with added CO2. During phase I the estimated gross primary production (GPP) was similar to 100 mmol C m(-2) day(-1), from which 75-95% was respired, similar to 1% ended up in the TPC (including export), and 5-25% was added to the DOC pool. During phase II, the respiration loss increased to similar to 100% of GPP at the ambient CO2 concentration, whereas respiration was lower (85-95% of GPP) in the highest CO2 treatment. Bacterial production was similar to 30% lower, on average, at the highest CO2 concentration than in the controls during phases II and III. This resulted in a higher accumulation of DOC and lower reduction in the TPC pool in the elevated CO2 treatments at the end of phase II extending throughout phase III. The "extra" organic carbon at high CO2 remained fixed in an increasing biomass of small-sized plankton and in the DOC pool, and did not transfer into large, sinking aggregates. Our results revealed a clear effect of increasing CO2 on the carbon budget and mineralization, in particular under nutrient limited conditions. Lower carbon loss processes (respiration and bacterial remineralization) at elevated CO2 levels resulted in higher TPC and DOC pools than ambient CO2 concentration. These results highlight the importance of addressing not only net changes in carbon standing stocks but also carbon fluxes and budgets to better disentangle the effects of ocean acidification. Y1 - 2016 U6 - https://doi.org/10.5194/bg-13-6081-2016 SN - 1726-4170 SN - 1726-4189 VL - 13 SP - 6081 EP - 6093 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Cepakova, Zuzana A1 - Hrouzek, Pavel A1 - Ziskova, Eva A1 - Nuyanzina-Boldareva, Ekaterina A1 - Sorf, Michal A1 - Kozlikova-Zapomelova, Eliska A1 - Salka, Ivette A1 - Grossart, Hans-Peter A1 - Koblizek, Michal T1 - High turnover rates of aerobic anoxygenic phototrophs in European freshwater lakes JF - Environmental microbiology N2 - Aerobic Anoxygenic Phototrophic (AAP) bacteria are bacteriochlorophyll (BChl) a -containing organisms which use light energy to supplement their predominantly heterotrophic metabolism. Here, we investigated mortality and growth rates of AAP bacteria in three different freshwater lakes in Central Europe: the mountain lake Plesne, the oligo-mesotrophic Lake Stechlin and the forest pond Huntov. The mortality of AAP bacteria was estimated from diel changes of BChl a fluorescence. Net and gross growth rates were calculated from the increases in AAP cell numbers. The gross growth rates of AAP bacteria ranged from 0.38 to 5.6 d(-1), with the highest values observed during summer months. Simultaneously, the rapidly growing AAP cells have to cope with an intense grazing pressure by both zooplankton and protists. The presented results document that during the day, gross growth usually surpased mortality. Our results indicate that AAP bacteria utilize light energy under natural conditions to maintain rapid growth rates, which are balanced by a generally intense grazing pressure. Y1 - 2016 U6 - https://doi.org/10.1111/1462-2920.13475 SN - 1462-2912 SN - 1462-2920 VL - 18 SP - 5063 EP - 5071 PB - Wiley-Blackwell CY - Hoboken ER - TY - GEN A1 - Kettner, Marie Therese A1 - Oberbeckmann, Sonja A1 - Labrenz, Matthias A1 - Grossart, Hans-Peter T1 - The Eukaryotic Life on Microplastics in Brackish Ecosystems T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Microplastics (MP) constitute a widespread contaminant all over the globe. Rivers and wastewater treatment plants (WWTP) transport annually several million tons of MP into freshwaters, estuaries and oceans, where they provide increasing artificial surfaces for microbial colonization. As knowledge on MP-attached communities is insufficient for brackish ecosystems, we conducted exposure experiments in the coastal Baltic Sea, an in-flowing river and a WWTP within the drainage basin. While reporting on prokaryotic and fungal communities from the same set-up previously, we focus here on the entire eukaryotic communities. Using high-throughput 18S rRNA gene sequencing, we analyzed the eukaryotes colonizing on two types of MP, polyethylene and polystyrene, and compared them to the ones in the surrounding water and on a natural surface (wood). More than 500 different taxa across almost all kingdoms of the eukaryotic tree of life were identified on MP, dominated by Alveolata, Metazoa, and Chloroplastida. The eukaryotic community composition on MP was significantly distinct from wood and the surrounding water, with overall lower diversity and the potentially harmful dinoflagellate Pfiesteria being enriched on MP. Co-occurrence networks, which include prokaryotic and eukaryotic taxa, hint at possibilities for dynamic microbial interactions on MP. This first report on total eukaryotic communities on MP in brackish environments highlights the complexity of MP-associated biofilms, potentially leading to altered microbial activities and hence changes in ecosystem functions. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 741 KW - microeukaryotes KW - plastic-associated biofilms KW - Baltic Sea KW - polyethylene KW - polystyrene KW - diversity profiles KW - network analysis KW - next-generation sequencing Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434996 SN - 1866-8372 IS - 741 ER - TY - JOUR A1 - Kettner, Marie Therese A1 - Oberbeckmann, Sonja A1 - Labrenz, Matthias A1 - Grossart, Hans-Peter T1 - The Eukaryotic Life on Microplastics in Brackish Ecosystems JF - Frontiers in Microbiology N2 - Microplastics (MP) constitute a widespread contaminant all over the globe. Rivers and wastewater treatment plants (WWTP) transport annually several million tons of MP into freshwaters, estuaries and oceans, where they provide increasing artificial surfaces for microbial colonization. As knowledge on MP-attached communities is insufficient for brackish ecosystems, we conducted exposure experiments in the coastal Baltic Sea, an in-flowing river and a WWTP within the drainage basin. While reporting on prokaryotic and fungal communities from the same set-up previously, we focus here on the entire eukaryotic communities. Using high-throughput 18S rRNA gene sequencing, we analyzed the eukaryotes colonizing on two types of MP, polyethylene and polystyrene, and compared them to the ones in the surrounding water and on a natural surface (wood). More than 500 different taxa across almost all kingdoms of the eukaryotic tree of life were identified on MP, dominated by Alveolata, Metazoa, and Chloroplastida. The eukaryotic community composition on MP was significantly distinct from wood and the surrounding water, with overall lower diversity and the potentially harmful dinoflagellate Pfiesteria being enriched on MP. Co-occurrence networks, which include prokaryotic and eukaryotic taxa, hint at possibilities for dynamic microbial interactions on MP. This first report on total eukaryotic communities on MP in brackish environments highlights the complexity of MP-associated biofilms, potentially leading to altered microbial activities and hence changes in ecosystem functions. KW - microeukaryotes KW - plastic-associated biofilms KW - Baltic Sea KW - polyethylene KW - polystyrene KW - diversity profiles KW - network analysis KW - next-generation sequencing Y1 - 2019 U6 - https://doi.org/10.3389/fmicb.2019.00538 SN - 1664-302X VL - 10 PB - Frontiers Media CY - Lausanne ER - TY - GEN A1 - Rojas-Jimenez, Keilor A1 - Rieck, Angelika A1 - Wurzbacher, Christian A1 - Jürgens, Klaus A1 - Labrenz, Matthias A1 - Grossart, Hans-Peter T1 - A Salinity Threshold Separating Fungal Communities in the Baltic Sea T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Salinity is a significant factor for structuring microbial communities, but little is known for aquatic fungi, particularly in the pelagic zone of brackish ecosystems. In this study, we explored the diversity and composition of fungal communities following a progressive salinity decline (from 34 to 3 PSU) along three transects of ca. 2000 km in the Baltic Sea, the world’s largest estuary. Based on 18S rRNA gene sequence analysis, we detected clear changes in fungal community composition along the salinity gradient and found significant differences in composition of fungal communities established above and below a critical value of 8 PSU. At salinities below this threshold, fungal communities resembled those from freshwater environments, with a greater abundance of Chytridiomycota, particularly of the orders Rhizophydiales, Lobulomycetales, and Gromochytriales. At salinities above 8 PSU, communities were more similar to those from marine environments and, depending on the season, were dominated by a strain of the LKM11 group (Cryptomycota) or by members of Ascomycota and Basidiomycota. Our results highlight salinity as an important environmental driver also for pelagic fungi, and thus should be taken into account to better understand fungal diversity and ecological function in the aquatic realm. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 739 KW - fungal diversity KW - baltic sea KW - salinity gradient KW - brackish waters KW - chytridiomycota KW - cryptomycota Y1 - 1019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434937 SN - 1866-8372 IS - 739 ER - TY - JOUR A1 - Rojas-Jimenez, Keilor A1 - Rieck, Angelika A1 - Wurzbacher, Christian A1 - Jürgens, Klaus A1 - Labrenz, Matthias A1 - Grossart, Hans-Peter T1 - A Salinity Threshold Separating Fungal Communities in the Baltic Sea JF - Frontiers in Microbiology N2 - Salinity is a significant factor for structuring microbial communities, but little is known for aquatic fungi, particularly in the pelagic zone of brackish ecosystems. In this study, we explored the diversity and composition of fungal communities following a progressive salinity decline (from 34 to 3 PSU) along three transects of ca. 2000 km in the Baltic Sea, the world’s largest estuary. Based on 18S rRNA gene sequence analysis, we detected clear changes in fungal community composition along the salinity gradient and found significant differences in composition of fungal communities established above and below a critical value of 8 PSU. At salinities below this threshold, fungal communities resembled those from freshwater environments, with a greater abundance of Chytridiomycota, particularly of the orders Rhizophydiales, Lobulomycetales, and Gromochytriales. At salinities above 8 PSU, communities were more similar to those from marine environments and, depending on the season, were dominated by a strain of the LKM11 group (Cryptomycota) or by members of Ascomycota and Basidiomycota. Our results highlight salinity as an important environmental driver also for pelagic fungi, and thus should be taken into account to better understand fungal diversity and ecological function in the aquatic realm. KW - fungal diversity KW - baltic sea KW - salinity gradient KW - brackish waters KW - chytridiomycota KW - cryptomycota Y1 - 2019 U6 - https://doi.org/10.3389/fmicb.2019.00680 SN - 1664-302X VL - 10 PB - Frontiers Media CY - Lausanne ER - TY - INPR A1 - Chattopadhyay, Madhab K. A1 - Chakraborty, Ranadhir A1 - Grossart, Hans-Peter A1 - Reddy, Gundlapally S. A1 - Jagannadham, Medicharla V. T1 - Antibiotic resistance of bacteria T2 - BioMed research international Y1 - 2015 U6 - https://doi.org/10.1155/2015/501658 SN - 2314-6133 SN - 2314-6141 PB - Hindawi Publishing Corp. CY - New York ER - TY - JOUR A1 - Corno, Gianluca A1 - Salka, Ivette A1 - Pohlmann, Kirsten A1 - Hall, Alex R. A1 - Grossart, Hans-Peter T1 - Interspecific interactions drive chitin and cellulose degradation by aquatic microorganisms JF - Aquatic microbial ecology : international journal N2 - Complex biopolymers (BPs) such as chitin and cellulose provide the majority of organic carbon in aquatic ecosystems, but the mechanisms by which communities of bacteria in natural systems exploit them are unclear. Previous degradation experiments in artificial systems predominantly used microcosms containing a single bacterial species, neglecting effects of interspecific interactions. By constructing simplified aquatic microbial communities, we tested how the addition of other bacterial species, of a nanoflagellate protist capable of consuming bacteria, or of both, affect utilization of BPs. Surprisingly, total abundance of resident bacteria in mixed communities increased upon addition of the protist. Concomitantly, bacteria shifted from free-living to aggregated morphotypes that seemed to promote utilization of BPs. In our model system, these interactions significantly increased productivity in terms of overall bacterial numbers and carbon transfer efficiency. This indicates that interactions on microbial aggregates may be crucial for chitin and cellulose degradation. We therefore suggest that interspecific microbial interactions must be considered when attempting to model the turnover of the vast pool of complex biopolymers in aquatic ecosystems. KW - Aggregation KW - Flagellate grazing KW - Ecological interactions KW - Microbial carbon transfer KW - Polymer degradation KW - System ecology Y1 - 2015 U6 - https://doi.org/10.3354/ame01765 SN - 0948-3055 SN - 1616-1564 VL - 76 IS - 1 SP - 27 EP - + PB - Institute of Mathematical Statistics CY - Oldendorf Luhe ER -