Genomic composition and dynamics among Methanomicrobiales predict adaptation to contrasting environments

作者：Patrick Denis Browne, Hideyuki Tamaki, Nikos C. Kyrpides, Tanja Woyke, Lynne Goodwin, Hiroyuki Imachi, Suzanna L. Bräuer, Joseph B. Yavitt, Wen‐Tso Liu, Stephen H. Zinder, Hinsby Cadillo‐Quiroz · 发表于：The ISME Journal · 年份：2016 · DOI：10.1038/ismej.2016.104 · 被引用次数：49 · 研究领域：Methane Hydrates and Related Phenomena、Microbial metabolism and enzyme function、Anaerobic Digestion and Biogas Production

Abstract Members of the order Methanomicrobiales are abundant, and sometimes dominant, hydrogenotrophic (H2-CO2 utilizing) methanoarchaea in a broad range of anoxic habitats. Despite their key roles in greenhouse gas emissions and waste conversion to methane, little is known about the physiological and genomic bases for their widespread distribution and abundance. In this study, we compared the genomes of nine diverse Methanomicrobiales strains, examined their pangenomes, reconstructed gene flow and identified genes putatively mediating their success across different habitats. Most strains slowly increased gene content whereas one, Methanocorpusculum labreanum, evidenced genome downsizing. Peat-dwelling Methanomicrobiales showed adaptations centered on improved transport of scarce inorganic nutrients and likely use H+ rather than Na+ transmembrane chemiosmotic gradients during energy conservation. In contrast, other Methanomicrobiales show the potential to concurrently use Na+ and H+ chemiosmotic gradients. Analyses also revealed that the Methanomicrobiales lack a canonical electron bifurcation system (MvhABGD) known to produce low potential electrons in other orders of hydrogenotrophic methanogens. Additional putative differences in anabolic metabolism suggest that the dynamics of interspecies electron transfer from Methanomicrobiales syntrophic partners can also differ considerably. Altogether, these findings suggest profound differences in electron trafficking in the Metha...