Appalachian State University, Department of Biology, ASU Box 32027, 572 Rivers Street, Boone, NC 28608-2027 USA.
Laurentian University, Department of Biology and the Vale Living with Lakes Centre, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada.
FEMS Microbiol Lett. 2020 Nov 5;367(20). doi: 10.1093/femsle/fnaa172.
Methane emission feedbacks in wetlands are predicted to influence global climate under climate change and other anthropogenic stressors. Herein, we review the taxonomy and physiological ecology of the microorganisms responsible for methane production in peatlands. Common in peat soils are five of the eight described orders of methanogens spanning three phyla (Euryarchaeota, Halobacterota and Thermoplasmatota). The phylogenetic affiliation of sequences found in peat suggest that members of the thus-far-uncultivated group Candidatus Bathyarchaeota (representing a fourth phylum) may be involved in methane cycling, either anaerobic oxidation of methane and/or methanogenesis, as at least a few organisms within this group contain the essential gene, mcrA, according to metagenomic data. Methanogens in peatlands are notoriously challenging to enrich and isolate; thus, much remains unknown about their physiology and how methanogen communities will respond to environmental changes. Consistent patterns of changes in methanogen communities have been reported across studies in permafrost peatland thaw where the resulting degraded feature is thermokarst. However much remains to be understood regarding methanogen community feedbacks to altered hydrology and warming in other contexts, enhanced atmospheric pollution (N, S and metals) loading and direct anthropogenic disturbances to peatlands like drainage, horticultural peat extraction, forestry and agriculture, as well as post-disturbance reclamation.
湿地中的甲烷排放反馈预计会在气候变化和其他人为压力下影响全球气候。在此，我们回顾了负责泥炭地甲烷产生的微生物的分类学和生理生态学。在泥炭土壤中，常见的有描述的产甲烷菌的八个目中的五个，跨越三个门（古菌门、盐杆菌门和热原体门）。在泥炭中发现的序列的系统发育归属表明，迄今为止尚未培养的候选古菌门（代表第四门）的成员可能参与甲烷循环，无论是甲烷的厌氧氧化还是产甲烷作用，因为根据宏基因组数据，该组中的至少一些生物体含有必需基因 mcrA。泥炭地中的产甲烷菌很难富集和分离；因此，它们的生理学以及产甲烷菌群落将如何对环境变化做出反应，仍然知之甚少。在多年冻土泥炭地解冻的研究中，已经报道了产甲烷菌群落变化的一致模式，其结果是热喀斯特退化特征。然而，在其他情况下，关于改变水文学和变暖对产甲烷菌群落的反馈，增强的大气污染（氮、硫和金属）负荷以及对泥炭地的直接人为干扰，如排水、园艺泥炭开采、林业和农业，以及干扰后的开垦，仍有许多需要了解。
