title: Diversity of aerobic methanotrophic bacteria in a permafrost active layer soil of the Lena Delta, Siberia.
abstract: With this study, we present first data on the diversity of aerobic methanotrophic bacteria (MOB) in an Arctic permafrost active layer soil of the Lena Delta, Siberia. Applying denaturing gradient gel electrophoresis and cloning of 16S ribosomal ribonucleic acid (rRNA) and pmoA gene fragments of active layer samples, we found a general restriction of the methanotrophic diversity to sequences closely related to the genera Methylobacter and Methylosarcina, both type I MOB. In contrast, we revealed a distinct species-level diversity. Based on phylogenetic analysis of the 16S rRNA gene, two new clusters of MOB specific for the permafrost active layer soil of this study were found. In total, 8 out of 13 operational taxonomic units detected belong to these clusters. Members of these clusters were closely related to Methylobacter psychrophilus and Methylobacter tundripaludum, both isolated from Arctic environments. A dominance of MOB closely related to M. psychrophilus and M. tundripaludum was confirmed by an additional pmoA gene analysis. We used diversity indices such as the Shannon diversity index or the Chao1 richness estimator in order to compare the MOB community near the surface and near the permafrost table. We determined a similar diversity of the MOB community in both depths and suggest that it is not influenced by the extreme physical and geochemical gradients in the active layer.
authors.affiliation: Alfred Wegener Institute for Polar and Marine Research, Research Department Potsdam, Telegrafenberg A43, 14473, Potsdam, Germany. Susanne.Liebner@awi.de
authors.forename: Susanne
authors.initials: S
authors.lastname: Liebner
authors.forename: Katja
authors.initials: K
authors.lastname: Rublack
authors.forename: Torben
authors.initials: T
authors.lastname: Stuehrmann
authors.forename: Dirk
authors.initials: D
authors.lastname: Wagner
mesh_terms: D000332:Aerobiosis; D001110:Arctic Regions; D004269:DNA, Bacterial / Q000032:analysis*; D004275:DNA, Ribosomal / Q000032:analysis; D014644:Genetic Variation; D007053:Ice; D008697:Methane / Q000378:metabolism*; D008772:Methylococcaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010105:Oxygenases / Q000235:genetics; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012800:Siberia; D012987:Soil; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D007053:Ice; D012336:RNA, Ribosomal, 16S; D012987:Soil; D010105:Oxygenases; C021555:methane monooxygenase; D008697:Methane