@misc{MantzoukiLuerlingFastneretal.2018, author = {Mantzouki, Evanthia and L{\"u}rling, Miquel and Fastner, Jutta and Domis, Lisette Nicole de Senerpont and Wilk-Wo{\'{z}}niak, Elżbieta and Koreiviene, Judita and Seelen, Laura and Teurlincx, Sven and Verstijnen, Yvon and Krztoń, Wojciech and Walusiak, Edward and Karosienė, Jūratė and Kasperovičienė, Jūratė and Savadova, Ksenija and Vitonytė, Irma and Cillero-Castro, Carmen and Budzyńska, Agnieszka and Goldyn, Ryszard and Kozak, Anna and Rosińska, Joanna and Szeląg-Wasielewska, Elżbieta and Domek, Piotr and Jakubowska-Krepska, Natalia and Kwasizur, Kinga and Messyasz, Beata and Pełechata, Aleksandra and Pełechaty, Mariusz and Kokocinski, Mikolaj and Garc{\´i}a-Murcia, Ana and Real, Monserrat and Romans, Elvira and Noguero-Ribes, Jordi and Duque, David Parre{\~n}o and Fern{\´a}ndez-Mor{\´a}n, El{\´i}sabeth and Karakaya, Nusret and H{\"a}ggqvist, Kerstin and Beklioğlu, Meryem and Filiz, Nur and Levi, Eti E. and Iskin, Uğur and Bezirci, Gizem and Tav{\c{s}}anoğlu, {\"U}lk{\"u} Nihan and {\"O}zhan, Koray and Gkelis, Spyros and Panou, Manthos and Fakioglu, {\"O}zden and Avagianos, Christos and Kaloudis, Triantafyllos and {\c{C}}elik, Kemal and Yilmaz, Mete and Marc{\´e}, Rafael and Catal{\´a}n, Nuria and Bravo, Andrea G. and Buck, Moritz and Colom-Montero, William and Mustonen, Kristiina and Pierson, Don and Yang, Yang and Raposeiro, Pedro M. and Gon{\c{c}}alves, V{\´i}tor and Antoniou, Maria G. and Tsiarta, Nikoletta and McCarthy, Valerie and Perello, Victor C. and Feldmann, T{\~o}nu and Laas, Alo and Panksep, Kristel and Tuvikene, Lea and Gagala, Ilona and Mankiewicz-Boczek, Joana and Yağc{\i}, Meral Apayd{\i}n and {\c{C}}{\i}nar, Şakir and {\c{C}}apk{\i}n, Kadir and Yağc{\i}, Abdulkadir and Cesur, Mehmet and Bilgin, Fuat and Bulut, Cafer and Uysal, Rahmi and Obertegger, Ulrike and Boscaini, Adriano and Flaim, Giovanna and Salmaso, Nico and Cerasino, Leonardo and Richardson, Jessica and Visser, Petra M. and Verspagen, Jolanda M. H. and Karan, T{\"u}nay and Soylu, Elif Neyran and Mara{\c{s}}l{\i}oğlu, Faruk and Napi{\´o}rkowska-Krzebietke, Agnieszka and Ochocka, Agnieszka and Pasztaleniec, Agnieszka and Ant{\~a}o-Geraldes, Ana M. and Vasconcelos, Vitor and Morais, Jo{\~a}o and Vale, Micaela and K{\"o}ker, Latife and Ak{\c{c}}aalan, Reyhan and Albay, Meri{\c{c}} and Maronić, Dubravka Špoljarić and Stević, Filip and Pfeiffer, Tanja Žuna and Fonvielle, Jeremy Andre and Straile, Dietmar and Rothhaupt, Karl-Otto and Hansson, Lars-Anders and Urrutia-Cordero, Pablo and Bl{\´a}ha, Luděk and Geriš, Rodan and Fr{\´a}nkov{\´a}, Mark{\´e}ta and Ko{\c{c}}er, Mehmet Ali Turan and Alp, Mehmet Tahir and Remec-Rekar, Spela and Elersek, Tina and Triantis, Theodoros and Zervou, Sevasti-Kiriaki and Hiskia, Anastasia and Haande, Sigrid and Skjelbred, Birger and Madrecka, Beata and Nemova, Hana and Drastichova, Iveta and Chomova, Lucia and Edwards, Christine and Sevindik, Tuğba Ongun and Tunca, Hatice and {\"O}nem, Bur{\c{c}}in and Aleksovski, Boris and Krstić, Svetislav and Vucelić, Itana Bokan and Nawrocka, Lidia and Salmi, Pauliina and Machado-Vieira, Danielle and Oliveira, Alinne Gurj{\~a}o De and Delgado-Mart{\´i}n, Jordi and Garc{\´i}a, David and Cereijo, Jose Lu{\´i}s and Gom{\`a}, Joan and Trapote, Mari Carmen and Vegas-Vilarr{\´u}bia, Teresa and Obrador, Biel and Grabowska, Magdalena and Karpowicz, Maciej and Chmura, Damian and {\´U}beda, B{\´a}rbara and G{\´a}lvez, Jos{\´e} {\´A}ngel and {\"O}zen, Arda and Christoffersen, Kirsten Seestern and Warming, Trine Perlt and Kobos, Justyna and Mazur-Marzec, Hanna and P{\´e}rez-Mart{\´i}nez, Carmen and Ramos-Rodr{\´i}guez, Elo{\´i}sa and Arvola, Lauri and Alcaraz-P{\´a}rraga, Pablo and Toporowska, Magdalena and Pawlik-Skowronska, Barbara and Nied{\'{z}}wiecki, Michał and Pęczuła, Wojciech and Leira, Manel and Hern{\´a}ndez, Armand and Moreno-Ostos, Enrique and Blanco, Jos{\´e} Mar{\´i}a and Rodr{\´i}guez, Valeriano and Montes-P{\´e}rez, Jorge Juan and Palomino, Roberto L. and Rodr{\´i}guez-P{\´e}rez, Estela and Carballeira, Rafael and Camacho, Antonio and Picazo, Antonio and Rochera, Carlos and Santamans, Anna C. and Ferriol, Carmen and Romo, Susana and Soria, Juan Miguel and Dunalska, Julita and Sieńska, Justyna and Szymański, Daniel and Kruk, Marek and Kostrzewska-Szlakowska, Iwona and Jasser, Iwona and Žutinić, Petar and Udovič, Marija Gligora and Plenković-Moraj, Anđelka and Frąk, Magdalena and Bańkowska-Sobczak, Agnieszka and Wasilewicz, Michał and {\"O}zkan, Korhan and Maliaka, Valentini and Kangro, Kersti and Grossart, Hans-Peter and Paerl, Hans W. and Carey, Cayelan C. and Ibelings, Bas W.}, title = {Temperature effects explain continental scale distribution of cyanobacterial toxins}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1105}, issn = {1866-8372}, doi = {10.25932/publishup-42790}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427902}, pages = {26}, year = {2018}, abstract = {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.}, language = {en} } @article{BjornerasWeyhenmeyerEvansetal.2017, author = {Bjorneras, C. and Weyhenmeyer, G. A. and Evans, C. D. and Gessner, M. O. and Grossart, Hans-Peter and Kangur, K. and Kokorite, I. and Kortelainen, P. and Laudon, H. and Lehtoranta, J. and Lottig, N. and Monteith, D. T. and Noges, P. and Noges, T. and Oulehle, F. and Riise, G. and Rusak, J. A. and Raike, A. and Sire, J. and Sterling, S. and Kritzberg, E. S.}, title = {Widespread Increases in Iron Concentration in European and North American Freshwaters}, series = {Global biogeochemical cycles}, volume = {31}, journal = {Global biogeochemical cycles}, publisher = {American Geophysical Union}, address = {Washington}, issn = {0886-6236}, doi = {10.1002/2017GB005749}, pages = {1488 -- 1500}, year = {2017}, abstract = {Recent reports of increasing iron (Fe) concentrations in freshwaters are of concern, given the fundamental role of Fe in biogeochemical processes. Still, little is known about the frequency and geographical distribution of Fe trends or about the underlying drivers. We analyzed temporal trends of Fe concentrations across 340 water bodies distributed over 10 countries in northern Europe and North America in order to gain a clearer understanding of where, to what extent, and why Fe concentrations are on the rise. We found that Fe concentrations have significantly increased in 28\% of sites, and decreased in 4\%, with most positive trends located in northern Europe. Regions with rising Fe concentrations tend to coincide with those with organic carbon (OC) increases. Fe and OC increases may not be directly mechanistically linked, but may nevertheless be responding to common regional-scale drivers such as declining sulfur deposition or hydrological changes. A role of hydrological factors was supported by covarying trends in Fe and dissolved silica, as these elements tend to stem from similar soil depths. A positive relationship between Fe increases and conifer cover suggests that changing land use and expanded forestry could have contributed to enhanced Fe export, although increases were also observed in nonforested areas. We conclude that the phenomenon of increasing Fe concentrations is widespread, especially in northern Europe, with potentially significant implications for wider ecosystem biogeochemistry, and for the current browning of freshwaters.}, language = {en} } @article{LischkeMehnerHiltetal.2017, author = {Lischke, Betty and Mehner, Thomas and Hilt, Sabine and Attermeyer, Katrin and Brauns, Mario and Brothers, Soren M. and Grossart, Hans-Peter and Koehler, Jan and Scharnweber, Inga Kristin and Gaedke, Ursula}, title = {Benthic carbon is inefficiently transferred in the food webs of two eutrophic shallow lakes}, series = {Freshwater biology}, volume = {62}, journal = {Freshwater biology}, publisher = {Wiley}, address = {Hoboken}, issn = {0046-5070}, doi = {10.1111/fwb.12979}, pages = {1693 -- 1706}, year = {2017}, abstract = {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.}, language = {en} } @article{AttermeyerGrossartFluryetal.2017, author = {Attermeyer, Katrin and Grossart, Hans-Peter and Flury, Sabine and Premke, Katrin}, title = {Bacterial processes and biogeochemical changes in the water body of kettle holes - mainly driven by autochthonous organic matter?}, series = {Aquatic sciences : research across boundaries}, volume = {79}, journal = {Aquatic sciences : research across boundaries}, publisher = {Springer}, address = {Basel}, issn = {1015-1621}, doi = {10.1007/s00027-017-0528-1}, pages = {675 -- 687}, year = {2017}, abstract = {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.}, language = {en} } @article{WurzbacherAttermeyerKettneretal.2017, author = {Wurzbacher, Christian and Attermeyer, Katrin and Kettner, Marie Therese and Flintrop, Clara and Warthmann, Norman and Hilt, Sabine and Grossart, Hans-Peter and Monaghan, Michael T.}, title = {DNA metabarcoding of unfractionated water samples relates phyto-, zoo- and bacterioplankton dynamics and reveals a single-taxon bacterial bloom}, series = {Environmental microbiology reports}, volume = {9}, journal = {Environmental microbiology reports}, publisher = {Wiley}, address = {Hoboken}, issn = {1758-2229}, doi = {10.1111/1758-2229.12540}, pages = {383 -- 388}, year = {2017}, abstract = {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.}, language = {en} } @article{HornakKasalickySimeketal.2017, author = {Hornak, Karel and Kasalicky, Vojtech and Simek, Karel and Grossart, Hans-Peter}, title = {Strain-specific consumption and transformation of alga-derived dissolved organic matter by members of the Limnohabitans-C and Polynucleobacter-B clusters of Betaproteobacteria}, series = {Environmental microbiology}, volume = {19}, journal = {Environmental microbiology}, publisher = {Wiley}, address = {Hoboken}, issn = {1462-2912}, doi = {10.1111/1462-2920.13900}, pages = {4519 -- 4535}, year = {2017}, abstract = {We investigated changes in quality and quantity of extracellular and biomass-derived organic matter (OM) from three axenic algae (genera Rhodomonas, Chlamydomonas, Coelastrum) during growth of Limnohabitans parvus, Limnohabitans planktonicus and Polynucleobacter acidiphobus representing important clusters of freshwater planktonic Betaproteobacteria. Total extracellular and biomass-derived OM concentrations from each alga were approximately 20 mg l(-1) and 1 mg l(-1) respectively, from which up to 9\% could be identified as free carbohydrates, polyamines, or free and combined amino acids. Carbohydrates represented 54\%-61\% of identified compounds of the extracellular OM from each alga. In biomass-derived OM of Rhodomonas and Chlamydomonas 71\%-77\% were amino acids and polyamines, while in that of Coelastrum 85\% were carbohydrates. All bacteria grew on alga-derived OM of Coelastrum, whereas only Limnohabitans strains grew on OM from Rhodomonas and Chlamydomonas. Bacteria consumed 24\%-76\% and 38\%-82\% of all identified extracellular and biomass-derived OM compounds respectively, and their consumption was proportional to the concentration of each OM compound in the different treatments. The bacterial biomass yield was higher than the total identifiable OM consumption indicating that bacteria also utilized other unidentified alga-derived OM compounds. Bacteria, however, also produced specific OM compounds suggesting enzymatic polymer degradation or de novo exudation.}, language = {en} } @article{KettnerRojasJimenezOberbeckmannetal.2017, author = {Kettner, Marie Therese and Rojas-Jimenez, Keilor and Oberbeckmann, Sonja and Labrenz, Matthias and Grossart, Hans-Peter}, title = {Microplastics alter composition of fungal communities in aquatic ecosystems}, series = {Environmental microbiology}, volume = {19}, journal = {Environmental microbiology}, publisher = {Wiley}, address = {Hoboken}, issn = {1462-2912}, doi = {10.1111/1462-2920.13891}, pages = {4447 -- 4459}, year = {2017}, abstract = {Despite increasing concerns about microplastic (MP) pollution in aquatic ecosystems, there is insufficient knowledge on how MP affect fungal communities. In this study, we explored the diversity and community composition of fungi attached to polyethylene (PE) and polystyrene (PS) particles incubated in different aquatic systems in north-east Germany: the Baltic Sea, the River Warnow and a wastewater treatment plant. Based on next generation 18S rRNA gene sequencing, 347 different operational taxonomic units assigned to 81 fungal taxa were identified on PE and PS. The MP-associated communities were distinct from fungal communities in the surrounding water and on the natural substrate wood. They also differed significantly among sampling locations, pointing towards a substrate and location specific fungal colonization. Members of Chytridiomycota, Cryptomycota and Ascomycota dominated the fungal assemblages, suggesting that both parasitic and saprophytic fungi thrive in MP biofilms. Thus, considering the worldwide increasing accumulation of plastic particles as well as the substantial vector potential of MP, especially these fungal taxa might benefit from MP pollution in the aquatic environment with yet unknown impacts on their worldwide distribution, as well as biodiversity and food web dynamics at large.}, language = {en} } @article{AmalfitanoCornoEckertetal.2017, author = {Amalfitano, Stefano and Corno, Gianluca and Eckert, Ester and Fazi, Stefano and Ninio, Shira and Callieri, Cristiana and Grossart, Hans-Peter and Eckert, Werner}, title = {Tracing particulate matter and associated microorganisms in freshwaters}, series = {Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica}, volume = {800}, journal = {Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica}, publisher = {Springer}, address = {Dordrecht}, issn = {0018-8158}, doi = {10.1007/s10750-017-3260-x}, pages = {145 -- 154}, year = {2017}, abstract = {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.}, language = {en} } @article{TangFluryGrossartetal.2017, author = {Tang, Kam W. and Flury, Sabine and Grossart, Hans-Peter and McGinnis, Daniel F.}, title = {The Chaoborus pump: Migrating phantom midge larvae sustain hypolimnetic oxygen deficiency and nutrient internal loading in lakes}, series = {Water research}, volume = {122}, journal = {Water research}, publisher = {Elsevier}, address = {Oxford}, issn = {0043-1354}, doi = {10.1016/j.watres.2017.05.058}, pages = {36 -- 41}, year = {2017}, abstract = {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.}, language = {en} } @article{IonescuBizicIonescuDeMaioetal.2017, author = {Ionescu, Danny and Bizic-Ionescu, Mina and De Maio, Nicola and Cypionka, Heribert and Grossart, Hans-Peter}, title = {Community-like genome in single cells of the sulfur bacterium Achromatium oxaliferum}, series = {Nature Communications}, volume = {8}, journal = {Nature Communications}, publisher = {Nature Publ. Group}, address = {London}, issn = {2041-1723}, doi = {10.1038/s41467-017-00342-9}, pages = {9193 -- 9205}, year = {2017}, language = {en} } @article{KaylerPremkeGessleretal.2019, author = {Kayler, Zachary E. and Premke, Katrin and Gessler, Arthur and Gessner, Mark O. and Griebler, Christian and Hilt, Sabine and Klemedtsson, Leif and Kuzyakov, Yakov and Reichstein, Markus and Siemens, Jan and Totsche, Kai-Uwe and Tranvik, Lars and Wagner, Annekatrin and Weitere, Markus and Grossart, Hans-Peter}, title = {Integrating Aquatic and Terrestrial Perspectives to Improve Insights Into Organic Matter Cycling at the Landscape Scale}, series = {Frontiers in Earth Science}, volume = {7}, journal = {Frontiers in Earth Science}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {2296-6463}, doi = {10.3389/feart.2019.00127}, pages = {14}, year = {2019}, abstract = {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.}, language = {en} } @article{LundgreenJaspersTravingetal.2019, author = {Lundgreen, Regitze B. C. and Jaspers, Cornelia and Traving, Sachia J. and Ayala, Daniel J. and Lombard, Fabien and Grossart, Hans-Peter and Nielsen, Torkel G. and Munk, Peter and Riemann, Lasse}, title = {Eukaryotic and cyanobacterial communities associated with marine snow particles in the oligotrophic Sargasso Sea}, series = {Scientific reports}, volume = {9}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-019-45146-7}, pages = {12}, year = {2019}, abstract = {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.}, language = {en} } @article{MasigolKhodaparastWoodhouseetal.2019, author = {Masigol, Hossein and Khodaparast, Seyed Akbar and Woodhouse, Jason Nicholas and Rojas Jim{\´e}nez, Keilor and Fonvielle, Jeremy Andre and Rezakhani, Forough and Mostowfizadeh-Ghalamfarsa, Reza and Neubauer, Darshan and Goldhammer, Tobias and Grossart, Hans-Peter}, title = {The contrasting roles of aquatic fungi and oomycetes in the degradation and transformation of polymeric organic matter}, series = {Limnology and oceanography}, volume = {64}, journal = {Limnology and oceanography}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {0024-3590}, pages = {2662 -- 2678}, year = {2019}, abstract = {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.}, language = {en} } @article{NumbergerGanzertZoccaratoetal.2019, author = {Numberger, Daniela and Ganzert, Lars and Zoccarato, Luca and M{\"u}hldorfer, Kristin and Sauer, Sascha and Grossart, Hans-Peter and Greenwood, Alex D.}, title = {Characterization of bacterial communities in wastewater with enhanced taxonomic resolution by full-length 16S rRNA sequencing}, series = {Scientific reports}, volume = {9}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-019-46015-z}, pages = {14}, year = {2019}, abstract = {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.}, language = {en} } @article{NumbergerDreierVullioudetal.2019, author = {Numberger, Daniela and Dreier, Carole and Vullioud, Colin and Gabriel, G{\"u}lsah and Greenwood, Alex D. and Grossart, Hans-Peter}, title = {Recovery of influenza a viruses from lake water and sediments by experimental inoculation}, series = {PLoS one}, volume = {14}, journal = {PLoS one}, number = {5}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0216880}, pages = {13}, year = {2019}, abstract = {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).}, language = {en} } @article{TangBackhausRiemannetal.2019, author = {Tang, Kam W. and Backhaus, Liv and Riemann, Lasse and Koski, Marja and Grossart, Hans-Peter and Munk, Peter and Nielsen, Torkel Gissel}, title = {Copepod carcasses in the subtropical convergence zone of the Sargasso Sea}, series = {Journal of plankton research}, volume = {41}, journal = {Journal of plankton research}, number = {4}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0142-7873}, doi = {10.1093/plankt/fbz038}, pages = {549 -- 560}, year = {2019}, abstract = {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.}, language = {en} } @article{RojasJimenezGrossartCordesetal.2020, author = {Rojas-Jimenez, Keilor and Grossart, Hans-Peter and Cordes, Erik and Cort{\´e}s, Jorge}, title = {Fungal Communities in Sediments Along a Depth Gradient in the Eastern Tropical Pacific}, series = {Frontiers in Microbiology}, volume = {11}, journal = {Frontiers in Microbiology}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.575207}, pages = {9}, year = {2020}, abstract = {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.}, language = {en} } @misc{GrossartVandenWyngaertKagamietal.2019, author = {Grossart, Hans-Peter and Van den Wyngaert, Silke and Kagami, Maiko and Wurzbacher, Christian and Cunliffe, Michael and Rojas-Jimenz, Keilor}, title = {Fungi in aquatic ecosystems}, series = {Nature reviews. Microbiology}, volume = {17}, journal = {Nature reviews. Microbiology}, number = {6}, publisher = {Nature Publ. Group}, address = {Basingstoke}, issn = {1740-1526}, doi = {10.1038/s41579-019-0175-8}, pages = {339 -- 354}, year = {2019}, abstract = {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.}, language = {en} } @misc{NumbergerDreierVullioudetal.2019, author = {Numberger, Daniela and Dreier, Carola and Vullioud, Colin and Gabriel, Guelsah and Greenwood, Alex D. and Grossart, Hans-Peter}, title = {Correction: Recovery of influenza A viruses from lake water and sediments by experimental inoculation (vol 14, e0216880, 2019)}, series = {PLoS one}, volume = {14}, journal = {PLoS one}, number = {6}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0218882}, pages = {1}, year = {2019}, language = {en} } @article{TiegsCostelloIskenetal.2019, author = {Tiegs, Scott D. and Costello, David M. and Isken, Mark W. and Woodward, Guy and McIntyre, Peter B. and Gessner, Mark O. and Chauvet, Eric and Griffiths, Natalie A. and Flecker, Alex S. and Acuna, Vicenc and Albarino, Ricardo and Allen, Daniel C. and Alonso, Cecilia and Andino, Patricio and Arango, Clay and Aroviita, Jukka and Barbosa, Marcus V. M. and Barmuta, Leon A. and Baxter, Colden V. and Bell, Thomas D. C. and Bellinger, Brent and Boyero, Luz and Brown, Lee E. and Bruder, Andreas and Bruesewitz, Denise A. and Burdon, Francis J. and Callisto, Marcos and Canhoto, Cristina and Capps, Krista A. and Castillo, Maria M. and Clapcott, Joanne and Colas, Fanny and Colon-Gaud, Checo and Cornut, Julien and Crespo-Perez, Veronica and Cross, Wyatt F. and Culp, Joseph M. and Danger, Michael and Dangles, Olivier and de Eyto, Elvira and Derry, Alison M. and Diaz Villanueva, Veronica and Douglas, Michael M. and Elosegi, Arturo and Encalada, Andrea C. and Entrekin, Sally and Espinosa, Rodrigo and Ethaiya, Diana and Ferreira, Veronica and Ferriol, Carmen and Flanagan, Kyla M. and Fleituch, Tadeusz and Shah, Jennifer J. Follstad and Frainer, Andre and Friberg, Nikolai and Frost, Paul C. and Garcia, Erica A. and Lago, Liliana Garcia and Garcia Soto, Pavel Ernesto and Ghate, Sudeep and Giling, Darren P. and Gilmer, Alan and Goncalves, Jose Francisco and Gonzales, Rosario Karina and Graca, Manuel A. S. and Grace, Mike and Grossart, Hans-Peter and Guerold, Francois and Gulis, Vlad and Hepp, Luiz U. and Higgins, Scott and Hishi, Takuo and Huddart, Joseph and Hudson, John and Imberger, Samantha and Iniguez-Armijos, Carlos and Iwata, Tomoya and Janetski, David J. and Jennings, Eleanor and Kirkwood, Andrea E. and Koning, Aaron A. and Kosten, Sarian and Kuehn, Kevin A. and Laudon, Hjalmar and Leavitt, Peter R. and Lemes da Silva, Aurea L. and Leroux, Shawn J. and Leroy, Carri J. and Lisi, Peter J. and MacKenzie, Richard and Marcarelli, Amy M. and Masese, Frank O. and Mckie, Brendan G. and Oliveira Medeiros, Adriana and Meissner, Kristian and Milisa, Marko and Mishra, Shailendra and Miyake, Yo and Moerke, Ashley and Mombrikotb, Shorok and Mooney, Rob and Moulton, Tim and Muotka, Timo and Negishi, Junjiro N. and Neres-Lima, Vinicius and Nieminen, Mika L. and Nimptsch, Jorge and Ondruch, Jakub and Paavola, Riku and Pardo, Isabel and Patrick, Christopher J. and Peeters, Edwin T. H. M. and Pozo, Jesus and Pringle, Catherine and Prussian, Aaron and Quenta, Estefania and Quesada, Antonio and Reid, Brian and Richardson, John S. and Rigosi, Anna and Rincon, Jose and Risnoveanu, Geta and Robinson, Christopher T. and Rodriguez-Gallego, Lorena and Royer, Todd V. and Rusak, James A. and Santamans, Anna C. and Selmeczy, Geza B. and Simiyu, Gelas and Skuja, Agnija and Smykla, Jerzy and Sridhar, Kandikere R. and Sponseller, Ryan and Stoler, Aaron and Swan, Christopher M. and Szlag, David and Teixeira-de Mello, Franco and Tonkin, Jonathan D. and Uusheimo, Sari and Veach, Allison M. and Vilbaste, Sirje and Vought, Lena B. M. and Wang, Chiao-Ping and Webster, Jackson R. and Wilson, Paul B. and Woelfl, Stefan and Xenopoulos, Marguerite A. and Yates, Adam G. and Yoshimura, Chihiro and Yule, Catherine M. and Zhang, Yixin X. and Zwart, Jacob A.}, title = {Global patterns and drivers of ecosystem functioning in rivers and riparian zones}, series = {Science Advances}, volume = {5}, journal = {Science Advances}, number = {1}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {2375-2548}, doi = {10.1126/sciadv.aav0486}, pages = {8}, year = {2019}, abstract = {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.}, language = {en} }