@article{WenUngerJurasinskietal.2018,
  author    = {Wen, Xi and Unger, Viktoria and Jurasinski, Gerald and Koebsch, Franziska and Horn, Fabian and Rehder, Gregor and Sachs, Torsten and Zak, Dominik and Lischeid, Gunnar and Knorr, Klaus-Holger and Boettcher, Michael E. and Winkel, Matthias and Bodelier, Paul L. E. and Liebner, Susanne},
  title     = {Predominance of methanogens over methanotrophs in rewetted fens characterized by high methane emissions},
  series = {Biogeosciences},
  volume    = {15},
  journal   = {Biogeosciences},
  number    = {21},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1726-4170},
  doi       = {10.5194/bg-15-6519-2018},
  pages     = {6519 -- 6536},
  year      = {2018},
  abstract  = {The rewetting of drained peatlands alters peat geochemistry and often leads to sustained elevated methane emission. Although this methane is produced entirely by microbial activity, the distribution and abundance of methane-cycling microbes in rewetted peatlands, especially in fens, is rarely described. In this study, we compare the community composition and abundance of methane-cycling microbes in relation to peat porewater geochemistry in two rewetted fens in northeastern Germany, a coastal brackish fen and a freshwater riparian fen, with known high methane fluxes. We utilized 16S rRNA high-throughput sequencing and quantitative polymerase chain reaction (qPCR) on 16S rRNA, mcrA, and pmoA genes to determine microbial community composition and the abundance of total bacteria, methanogens, and methanotrophs. Electrical conductivity (EC) was more than 3 times higher in the coastal fen than in the riparian fen, averaging 5.3 and 1.5 mS cm(-1), respectively. Porewater concentrations of terminal electron acceptors (TEAs) varied within and among the fens. This was also reflected in similarly high intra- and inter-site variations of microbial community composition. Despite these differences in environmental conditions and electron acceptor availability, we found a low abundance of methanotrophs and a high abundance of methanogens, represented in particular by Methanosaetaceae, in both fens. This suggests that rapid (re) establishment of methanogens and slow (re) establishment of methanotrophs contributes to prolonged increased methane emissions following rewetting.},
  language  = {en}
}
@article{VuilleminHornFrieseetal.2018,
  author    = {Vuillemin, Aurele and Horn, Fabian and Friese, Andre and Winkel, Matthias and Alawi, Mashal and Wagner, Dirk and Henny, Cynthia and Orsi, William D. and Crowe, Sean A. and Kallmeyer, Jens},
  title     = {Metabolic potential of microbial communities from ferruginous sediments},
  series = {Environmental microbiology},
  volume    = {20},
  journal   = {Environmental microbiology},
  number    = {12},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1462-2912},
  doi       = {10.1111/1462-2920.14343},
  pages     = {4297 -- 4313},
  year      = {2018},
  abstract  = {Ferruginous (Fe-rich, SO4-poor) conditions are generally restricted to freshwater sediments on Earth today, but were likely widespread during the Archean and Proterozoic Eons. Lake Towuti, Indonesia, is a large ferruginous lake that likely hosts geochemical processes analogous to those that operated in the ferruginous Archean ocean. The metabolic potential of microbial communities and related biogeochemical cycling under such conditions remain largely unknown. We combined geochemical measurements (pore water chemistry, sulfate reduction rates) with metagenomics to link metabolic potential with geochemical processes in the upper 50 cm of sediment. Microbial diversity and quantities of genes for dissimilatory sulfate reduction (dsrAB) and methanogenesis (mcrA) decrease with increasing depth, as do rates of potential sulfate reduction. The presence of taxa affiliated with known iron- and sulfate-reducers implies potential use of ferric iron and sulfate as electron acceptors. Pore-water concentrations of acetate imply active production through fermentation. Fermentation likely provides substrates for respiration with iron and sulfate as electron donors and for methanogens that were detected throughout the core. The presence of ANME-1 16S and mcrA genes suggests potential for anaerobic methane oxidation. Overall our data suggest that microbial community metabolism in anoxic ferruginous sediments support coupled Fe, S and C biogeochemical cycling.},
  language  = {en}
}