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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 -