title: Methane turnover and methanotrophic communities in arctic aquatic ecosystems of the Lena Delta, Northeast Siberia.
abstract: Large amounts of organic carbon are stored in Arctic permafrost environments, and microbial activity can potentially mineralize this carbon into methane, a potent greenhouse gas. In this study, we assessed the methane budget, the bacterial methane oxidation (MOX) and the underlying environmental controls of arctic lake systems, which represent substantial sources of methane. Five lake systems located on Samoylov Island (Lena Delta, Siberia) and the connected river sites were analyzed using radiotracers to estimate the MOX rates, and molecular biology methods to characterize the abundance and the community composition of methane-oxidizing bacteria (MOB). In contrast to the river, the lake systems had high variation in the methane concentrations, the abundance and composition of the MOB communities, and consequently, the MOX rates. The highest methane concentrations and the highest MOX rates were detected in the lake outlets and in a lake complex in a flood plain area. Though, in all aquatic systems, we detected both, Type I and II MOB, in lake systems, we observed a higher diversity including MOB, typical of the soil environments. The inoculation of soil MOB into the aquatic systems, resulting from permafrost thawing, might be an additional factor controlling the MOB community composition and potentially methanotrophic capacity.
authors.affiliation: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Research Unit Potsdam, Telegrafenberg, 14473 Potsdam, Germany GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam, Section 5.3 Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany.
authors.forename: Roman
authors.initials: R
authors.lastname: Osudar
authors.affiliation: GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam, Section 5.3 Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Liebner
authors.affiliation: GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam, Section 5.3 Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany.
authors.forename: Mashal
authors.initials: M
authors.lastname: Alawi
authors.affiliation: GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam, Section 5.3 Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany.
authors.forename: Sizhong
authors.initials: S
authors.lastname: Yang
authors.affiliation: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Biological Station Helgoland, Kurpromenade 201, 27498 Helgoland, Germany.
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Bussmann
authors.affiliation: GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam, Section 5.3 Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany Dirk.Wagner@gfz-potsdam.de.
authors.forename: Dirk
authors.initials: D
authors.lastname: Wagner
mesh_terms: D001110:Arctic Regions; D001483:Base Sequence; D002244:Carbon / Q000378:metabolism; D057231:Climate Change; D004269:DNA, Bacterial / Q000235:genetics; D017753:Ecosystem; D017752:Greenhouse Effect; D060106:Lakes / Q000032:analysis* / Q000382:microbiology; D008697:Methane / Q000032:analysis / Q000378:metabolism*; D008772:Methylococcaceae / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis*; D045483:Rivers / Q000737:chemistry* / Q000382:microbiology; D017422:Sequence Analysis, DNA; D012800:Siberia; D012987:Soil; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D012987:Soil; D002244:Carbon; D008697:Methane; D010100:Oxygen
keywords: Samoylov Island; active layer soil; bacterial methane oxidation; global climate change; methane emission; pmoA; pyrosequencing