@article{NumbergerRiedelMcEwenetal.2019,
  author    = {Numberger, Daniela and Riedel, Thomas and McEwen, Gayle and N{\"u}bel, Ulrich and Frentrup, Martinique and Schober, Isabel and Bunk, Boyke and Spr{\"o}er, Cathrin and Overmann, J{\"o}rg and Grossart, Hans-Peter and Greenwood, Alex D.},
  title     = {Genomic analysis of three Clostridioides difficile isolates from urban water sources},
  series = {Anaerobe},
  volume    = {56},
  journal   = {Anaerobe},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {1075-9964},
  doi       = {10.1016/j.anaerobe.2019.01.002},
  pages     = {22 -- 26},
  year      = {2019},
  abstract  = {We investigated inflow of a wastewater treatment plant and sediment of an urban lake for the presence of Clostridioides difficile by cultivation and PCR. Among seven colonies we sequenced the complete genomes of three: two non-toxigenic isolates from wastewater and one toxigenic isolate from the urban lake. For all obtained isolates, a close genomic relationship with human-derived isolates was observed. (C) 2019 Elsevier Ltd. All rights reserved.},
  language  = {en}
}
@article{FrindteEckertAttermeyeretal.2013,
  author    = {Frindte, Katharina and Eckert, Werner and Attermeyer, Katrin and Grossart, Hans-Peter},
  title     = {Internal wave-induced redox shifts affect biogeochemistry and microbial activity in sediments - a simulation experiment},
  series = {Biogeochemistry},
  volume    = {113},
  journal   = {Biogeochemistry},
  number    = {1-3},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {0168-2563},
  doi       = {10.1007/s10533-012-9769-1},
  pages     = {423 -- 434},
  year      = {2013},
  abstract  = {Internal waves (seiches) are well-studied physical processes in stratified lakes, but their effects on sediment porewater chemistry and microbiology are still largely unexplored. Due to pycnocline oscillations, sediments are exposed to recurrent changes between epilimnetic and hypolimnetic water. This results in strong differences of environmental conditions, which should be reflected in the responses of redox-sensitive biogeochemical processes at both, the sediment-water interface and deeper sediment layers. We tested in a series of mesocosm experiments the influence of seiche-induced redox changes on porewater chemistry and bacterial activity in the sediments under well controlled conditions. Thereby, we excluded effects of changes in current and temperature regimes. For a period of 10 days, intact sediment cores from oligotrophic Lake Stechlin were incubated under constant (either oxic or anoxic) or alternating redox conditions. Solute concentrations were measured as porewater profiles in the sediment, while microbial activity was determined in the upper 0.5 cm of sediment. Oxic and alternating redox conditions resulted in similar ammonium, phosphate, and methane porewater concentrations, while concentrations of each analyte were considerably higher in anoxic cores. Microbial activity was clearly lower in the anoxic cores than in the oxic and the alternating cores. In conclusion, cores with intermittent anoxic phases of up to 24 hours do not differ in biogeochemistry and microbial activities from static oxic sediments. However, due to various physical processes seiches cause oxygen to penetrate deeper into sediment layers, which affects sediment redox gradients and increase microbial activity in seiche-influenced sediments.},
  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}
}