@article{ReilImholtRosenfeldetal.2017, author = {Reil, Daniela and Imholt, Christian and Rosenfeld, Ulrike and Drewes, Stephan and Fischer, S. and Heuser, Emil and Petraityte-Burneikiene, Rasa and Ulrich, R. G. and Jacob, J.}, title = {Validation of the Puumala virus rapid field test for bank voles in Germany}, series = {Epidemiology and infection}, volume = {145}, journal = {Epidemiology and infection}, number = {3}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {0950-2688}, doi = {10.1017/S0950268816002557}, pages = {434 -- 439}, year = {2017}, abstract = {Puumala virus (PUUV) causes many human infections in large parts of Europe and can lead to mild to moderate disease. The bank vole (Myodes glareolus) is the only reservoir of PUUV in Central Europe. A commercial PUUV rapid field test for rodents was validated for bank-vole blood samples collected in two PUUV-endemic regions in Germany (North Rhine-Westphalia and Baden-Wurttemberg). A comparison of the results of the rapid field test and standard ELISAs indicated a test efficacy of 93-95\%, largely independent of the origin of the antigens used in the ELISA. In ELISAs, reactivity for the German PUUV strain was higher compared to the Swedish strain but not compared to the Finnish strain, which was used for the rapid field test. In conclusion, the use of the rapid field test can facilitate short-term estimation of PUUV seroprevalence in bank-vole populations in Germany and can aid in assessing human PUUV infection risk.}, language = {en} } @article{ReilRosenfeldImholtetal.2017, author = {Reil, Daniela and Rosenfeld, Ulrike and Imholt, Christian and Schmidt, Sabrina and Ulrich, Rainer G. and Eccard, Jana and Jacob, Jens}, title = {Puumala hantavirus infections in bank vole populations}, series = {BMC ecology}, volume = {17}, journal = {BMC ecology}, publisher = {BioMed Central}, address = {London}, issn = {1472-6785}, doi = {10.1186/s12898-017-0118-z}, pages = {13}, year = {2017}, abstract = {Background In Europe, bank voles (Myodes glareolus) are widely distributed and can transmit Puumala virus (PUUV) to humans, which causes a mild to moderate form of haemorrhagic fever with renal syndrome, called nephropathia epidemica. Uncovering the link between host and virus dynamics can help to prevent human PUUV infections in the future. Bank voles were live trapped three times a year in 2010-2013 in three woodland plots in each of four regions in Germany. Bank vole population density was estimated and blood samples collected to detect PUUV specific antibodies. Results We demonstrated that fluctuation of PUUV seroprevalence is dependent not only on multi-annual but also on seasonal dynamics of rodent host abundance. Moreover, PUUV infection might affect host fitness, because seropositive individuals survived better from spring to summer than uninfected bank voles. Individual space use was independent of PUUV infections. Conclusions Our study provides robust estimations of relevant patterns and processes of the dynamics of PUUV and its rodent host in Central Europe, which are highly important for the future development of predictive models for human hantavirus infection risk}, language = {en} } @article{EckertDiCesareKettneretal.2017, author = {Eckert, Ester M. and Di Cesare, Andrea and Kettner, Marie Therese and Arias-Andres, Maria and Fontaneto, Diego and Grossart, Hans-Peter and Corno, Gianluca}, title = {Microplastics increase impact of treated wastewater on freshwater microbial community}, series = {Environmental pollution}, volume = {234}, journal = {Environmental pollution}, publisher = {Elsevier}, address = {Oxford}, issn = {0269-7491}, doi = {10.1016/j.envpol.2017.11.070}, pages = {495 -- 502}, year = {2017}, abstract = {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.}, language = {en} } @misc{KramerLenhard2017, author = {Kramer, Elena M. and Lenhard, Michael}, title = {Shape and form in plant development}, series = {Seminars in cell \& developmental biology}, volume = {79}, journal = {Seminars in cell \& developmental biology}, publisher = {Elsevier}, address = {London}, issn = {1084-9521}, doi = {10.1016/j.semcdb.2017.11.004}, pages = {1 -- 2}, year = {2017}, language = {en} } @article{VandenWyngaertSetoRojasJimenezetal.2017, author = {Van den Wyngaert, Silke and Seto, Kensuke and Rojas-Jimenez, Keilor and Kagami, Maiko and Grossart, Hans-Peter}, title = {A New Parasitic Chytrid, Staurastromyces oculus (Rhizophydiales, Staurastromy-cetaceae fam. nov.), Infecting the Freshwater Desmid Staurastrum sp.}, series = {Protist}, volume = {168}, journal = {Protist}, publisher = {Elsevier}, address = {Jena}, issn = {1434-4610}, doi = {10.1016/j.protis.2017.05.001}, pages = {392 -- 407}, year = {2017}, abstract = {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.}, language = {en} } @article{TaubeGanzertGrossartetal.2017, author = {Taube, Robert and Ganzert, Lars and Grossart, Hans-Peter and Gleixner, Gerd and Premke, Katrin}, title = {Organic matter quality structures benthic fatty acid patterns and the abundance of fungi and bacteria in temperate lakes}, series = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man}, volume = {610}, journal = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0048-9697}, doi = {10.1016/j.scitotenv.2017.07.256}, pages = {469 -- 481}, year = {2017}, abstract = {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.}, language = {en} } @article{RojasJimenezFonvielleMaetal.2017, author = {Rojas-Jimenez, Keilor and Fonvielle, Jeremy Andre and Ma, Hua and Grossart, Hans-Peter}, title = {Transformation of humic substances by the freshwater Ascomycete Cladosporium sp.}, series = {Waterbird}, volume = {40}, journal = {Waterbird}, publisher = {Waterbird SOC}, address = {Washington}, issn = {1524-4695}, doi = {10.1002/lno.10545}, pages = {282 -- 288}, year = {2017}, abstract = {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.}, language = {en} } @article{WurzbacherFuchsAttermeyeretal.2017, author = {Wurzbacher, Christian and Fuchs, Andrea and Attermeyer, Katrin and Frindte, Katharina and Grossart, Hans-Peter and Hupfer, Michael and Casper, Peter and Monaghan, Michael T.}, title = {Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment}, series = {Microbiome}, volume = {5}, journal = {Microbiome}, publisher = {BioMed Central}, address = {London}, issn = {2049-2618}, doi = {10.1186/s40168-017-0255-9}, pages = {16}, year = {2017}, abstract = {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.}, language = {en} } @article{WeyhenmeyerMackayStockwelletal.2017, author = {Weyhenmeyer, Gesa A. and Mackay, Murray and Stockwell, Jason D. and Thiery, Wim and Grossart, Hans-Peter and Augusto-Silva, Petala B. and Baulch, Helen M. and de Eyto, Elvira and Hejzlar, Josef and Kangur, Kuelli and Kirillin, Georgiy and Pierson, Don C. and Rusak, James A. and Sadro, Steven and Woolway, R. Iestyn}, title = {Citizen science shows systematic changes in the temperature difference between air and inland waters with global warming}, series = {Scientific reports}, volume = {7}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/srep43890}, pages = {9}, year = {2017}, abstract = {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.}, language = {en} } @article{McGinnisFluryTangetal.2017, author = {McGinnis, Daniel F. and Flury, Sabine and Tang, Kam W. and Grossart, Hans-Peter}, title = {Porewater methane transport within the gas vesicles of diurnally migrating Chaoborus spp.}, series = {Scientific reports}, volume = {7}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/srep44478}, pages = {7}, year = {2017}, abstract = {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.}, language = {en} }