Methanogenic archaea are main contributors to methane emissions, and have a crucial role in carbon cycling and global warming. Until recently, methanogens were confined to Euryarchaeota, but metagenomic studies revealed the presence of genes encoding the methyl coenzyme M reductase complex in other archaeal clades^1,2,3,4, thereby opening up the premise that methanogenesis is taxonomically more widespread. Nevertheless, laboratory cultivation of these non-euryarchaeal methanogens was lacking to corroborate their potential methanogenic ability and physiology. Here we report the isolation of a thermophilic archaeon LWZ-6 from an oil field. This archaeon belongs to the class Methanosuratincolia (originally affiliated with ‘Candidatus Verstraetearchaeota’) in the phylum Thermoproteota. Methanosuratincola petrocarbonis LWZ-6 is a strict hydrogen-dependent methylotrophic methanogen. Although previous metagenomic studies speculated on the fermentative potential of Methanosuratincolia members, strain LWZ-6 does not ferment sugars, peptides or amino acids. Its energy metabolism is linked only to methanogenesis, with methanol and monomethylamine as electron acceptors and hydrogen as an electron donor. Comparative (meta)genome analysis confirmed that hydrogen-dependent methylotrophic methanogenesis is a widespread trait among Methanosuratincolia. Our findings confirm that the diversity of methanogens expands beyond the classical Euryarchaeota and imply the importance of hydrogen-dependent methylotrophic methanogenesis in global methane emissions and carbon cycle.

产甲烷古菌是甲烷排放的主要贡献者，在碳循环和全球变暖中发挥着至关重要的作用。直到最近，产甲烷菌还仅限于广古菌门，但宏基因组研究揭示了其他古菌分支中存在编码甲基辅酶M还原酶复合物的基因 ^1,2,3,4 ，从而打开了产甲烷作用在分类学上更广泛的前提。然而，这些非广古菌产甲烷菌的实验室培养缺乏证实其潜在的产甲烷能力和生理学。在这里，我们报告了从油田分离出的嗜热古菌 LWZ-6。该古菌属于 Thermoproteota 门的 Methanosuratincolia 纲（最初隶属于“Candidatus Verstraetearchaeota”）。 Methanosuratincola petrocarbonis LWZ-6 是一种严格依赖氢的甲基营养产甲烷菌。尽管之前的宏基因组研究推测了 Methanosuratincolia 成员的发酵潜力，但菌株 LWZ-6 不发酵糖、肽或氨基酸。其能量代谢仅与产甲烷有关，以甲醇和一甲胺作为电子受体，以氢作为电子供体。比较（元）基因组分析证实，氢依赖性甲基营养产甲烷作用是 Methanosuratincolia 中的一个普遍特征。我们的研究结果证实，产甲烷菌的多样性超出了经典的广古菌门范围，这意味着依赖氢的甲基营养产甲烷作用在全球甲烷排放和碳循环中的重要性。