1] Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane 4072, Queensland, Australia [2] [3].
1] Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane 4072, Queensland, Australia [2].
Nat Commun. 2014;5:3212. doi: 10.1038/ncomms4212.
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.
多年冻土的融化会促进被低温封存的和新的碳的微生物降解，导致甲烷的生物产生，从而对气候变化产生正反馈。在这里，我们确定了瑞典北部多年冻土融化梯度上的微生物群落组成。部分融化的地点经常由单一的古菌生物型主导，即新的未培养的“Rice Cluster II”（Candidatus 'Methanoflorentaceae' 科）的“Candidatus 'Methanoflorens stordalenmirensis'”。宏基因组测序导致了其近完整基因组的恢复，揭示了产甲烷所需的氢营养型基因。这些基因高度表达，甲烷碳同位素数据与部分融化地点的氢营养型甲烷产生一致。除了多年冻土湿地外，“Methanoflorentaceae”在高甲烷通量生境中也广泛存在，这表明该谱系不仅普遍存在，而且是全球甲烷产生的主要贡献者。在多年冻土的融化过程中，“Candidatus 'M. stordalenmirensis'”似乎是甲烷产生的气候变暖正反馈的关键中介。
