title: Discovery of a novel methanogen prevalent in thawing permafrost.
abstract: Thawing permafrost promotes microbial degradation of cryo-sequestered and new carbon leading to the biogenic production of methane, creating a positive feedback to climate change. Here we determine microbial community composition along a permafrost thaw gradient in northern Sweden. Partially thawed sites were frequently dominated by a single archaeal phylotype, Candidatus 'Methanoflorens stordalenmirensis' gen. nov. sp. nov., belonging to the uncultivated lineage 'Rice Cluster II' (Candidatus 'Methanoflorentaceae' fam. nov.). Metagenomic sequencing led to the recovery of its near-complete genome, revealing the genes necessary for hydrogenotrophic methanogenesis. These genes are highly expressed and methane carbon isotope data are consistent with hydrogenotrophic production of methane in the partially thawed site. In addition to permafrost wetlands, 'Methanoflorentaceae' are widespread in high methane-flux habitats suggesting that this lineage is both prevalent and a major contributor to global methane production. In thawing permafrost, Candidatus 'M. stordalenmirensis' appears to be a key mediator of methane-based positive feedback to climate warming.
authors: 1] Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane 4072, Queensland, Australia [2] [3].
authors: Rhiannon
authors: R
authors: Mondav
authors: 1] Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane 4072, Queensland, Australia [2].
authors: Ben J
authors: BJ
authors: Woodcroft
authors: Department of Soil, Water and Environmental Science, University of Arizona, Tucson, Arizona 85721, USA.
authors: Eun-Hae
authors: EH
authors: Kim
authors: 1] Ecology and Evolutionary Biology Department, University of Arizona, Tucson, Arizona 85721, USA [2].
authors: Carmody K
authors: CK
authors: McCalley
authors: Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, Florida 32306-4320, USA.
authors: Suzanne B
authors: SB
authors: Hodgkins
authors: Department of Geological Sciences, Stockholm University, Stockholm 106 91, Sweden.
authors: Patrick M
authors: PM
authors: Crill
authors: Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, Florida 32306-4320, USA.
authors: Jeffrey
authors: J
authors: Chanton
authors: Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors: Gregory B
authors: GB
authors: Hurst
authors: 1] Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA [2].
authors: Nathan C
authors: NC
authors: VerBerkmoes
authors: Ecology and Evolutionary Biology Department, University of Arizona, Tucson, Arizona 85721, USA.
authors: Scott R
authors: SR
authors: Saleska
authors: Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane 4072, Queensland, Australia.
authors: Philip
authors: P
authors: Hugenholtz
authors: Department of Soil, Water and Environmental Science, University of Arizona, Tucson, Arizona 85721, USA.
authors: Virginia I
authors: VI
authors: Rich
authors: Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane 4072, Queensland, Australia.
authors: Gene W
authors: GW
authors: Tyson
mesh_terms: D001105:Archaea / Q000302:isolation & purification*; D001110:Arctic Regions; D057231:Climate Change; D008697:Methane / Q000378:metabolism*; D059013:Microbial Consortia; D065946:Permafrost / Q000382:microbiology*
chemical_list: D008697:Methane