Genomic Composition And Dynamics Among Methanomicrobiales Predict Adaptation To Contrasting Environments

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Suzanna Brauer Ph.D., Associate Professor (Creator)
Institution
Appalachian State University (ASU )
Web Site: https://library.appstate.edu/

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 Methanomicrobiales compared with other hydrogenotrophs, and warrant further functional evaluations.

Additional Information

Publication
Browne, P., Tamaki, H., Kyrpides, N. et al. Genomic composition and dynamics among Methanomicrobiales predict adaptation to contrasting environments. ISME J 11, 87–99 (2017). https://doi.org/10.1038/ismej.2016.104. Publisher version of record available at: https://www.nature.com/articles/ismej2016104
Language: English
Date: 2016
Keywords
Methanomicrobiales, greenhouse gas emissions, hydrogenotrophs, hydrogenotrophic methanogens

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