title: Archaeal and bacterial communities across a chronosequence of drained lake basins in Arctic Alaska.
abstract: We examined patterns in soil microbial community composition across a successional gradient of drained lake basins in the Arctic Coastal Plain. Analysis of 16S rRNA gene sequences revealed that methanogens closely related to Candidatus 'Methanoflorens stordalenmirensis' were the dominant archaea, comprising >50% of the total archaea at most sites, with particularly high levels in the oldest basins and in the top 57 cm of soil (active and transition layers). Bacterial community composition was more diverse, with lineages from OP11, Actinobacteria, Bacteroidetes, and Proteobacteria found in high relative abundance across all sites. Notably, microbial composition appeared to converge in the active layer, but transition and permafrost layer communities across the sites were significantly different to one another. Microbial biomass using fatty acid-based analysis indicated that the youngest basins had increased abundances of gram-positive bacteria and saprotrophic fungi at higher soil organic carbon levels, while the oldest basins displayed an increase in only the gram-positive bacteria. While this study showed differences in microbial populations across the sites relevant to basin age, the dominance of Candidatus 'M. stordalenmirensis' across the chronosequence indicates the potential for changes in local carbon cycling, depending on how these methanogens and associated microbial communities respond to warming temperatures.
authors.affiliation: Cornell University, School of Integrative Plant Science, Ithaca, NY 14853, United States.
authors.forename: J
authors.initials: J
authors.lastname: Kao-Kniffin
authors.affiliation: University of Queensland, Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, Brisbane 4072, Queensland, Australia.
authors.forename: B J
authors.initials: BJ
authors.lastname: Woodcroft
authors.affiliation: Cornell University, School of Integrative Plant Science, Ithaca, NY 14853, United States.
authors.forename: S M
authors.initials: SM
authors.lastname: Carver
authors.affiliation: University of Wisconsin-Madison, Department of Soil Science, Madison, WI 53706, United States.
authors.forename: J G
authors.initials: JG
authors.lastname: Bockheim
authors.affiliation: Yale University, Department of Molecular, Cellular, and Developmental Biology, New Haven, CT 06520, United States.
authors.forename: J
authors.initials: J
authors.lastname: Handelsman
authors.affiliation: University of Queensland, Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, Brisbane 4072, Queensland, Australia.
authors.forename: G W
authors.initials: GW
authors.lastname: Tyson
authors.affiliation: University of Cincinnati, Department of Geography, Cincinnati, Ohio, 45221, United States.
authors.forename: K M
authors.initials: KM
authors.lastname: Hinkel
authors.affiliation: Technische Universitaet Muenchen (TUM), Lehrstuhl fuer Bodenkunde, 85354 Freising, Germany.
authors.forename: C W
authors.initials: CW
authors.lastname: Mueller
mesh_terms: D000413:Alaska; D001105:Archaea / Q000235:genetics* / Q000302:isolation & purification; D001110:Arctic Regions; D001419:Bacteria / Q000235:genetics* / Q000302:isolation & purification; D018533:Biomass; D030541:Databases, Genetic; D060106:Lakes / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
chemical_list: D012336:RNA, Ribosomal, 16S