Journal
ISME JOURNAL
Volume 8, Issue 5, Pages 1069-1078Publisher
SPRINGERNATURE
DOI: 10.1038/ismej.2013.212
Keywords
methane oxidation; electron transportation; single aggregate genome; metatranscriptome; methanogenesis
Categories
Funding
- National Basic Research Program of China [2011CB808800]
- National Natural Science Foundation of China [91228201, 31290232]
- National High-Tech Program [2012AA092103-2]
- European Science Foundation MicroSYSTEMS - Fondsvoor Wetenschappelijk Onderzoek [506G.0656.05]
- Geconcerteerde Onderzoeks actie (GOA) of Ghent University [BOF09/GOA/005]
Ask authors/readers for more resources
Anaerobic oxidation of methane (AOM) is a crucial process limiting the flux of methane from marine environments to the atmosphere. The process is thought to be mediated by three groups of uncultivated methane-oxidizing archaea (ANME-1, 2 and 3). Although the responsible microbes have been intensively studied for more than a decade, central mechanistic details remain unresolved. On the basis of an integrated analysis of both environmental metatranscriptome and single-aggregate genome of a highly active AOM enrichment dominated by ANME-2a, we provide evidence for a complete and functioning AOM pathway in ANME-2a. All genes required for performing the seven steps of methanogenesis from CO2 were found present and actively expressed. Meanwhile, genes for energy conservation and electron transportation including those encoding F420H2 dehydrogenase (Fpo), the cytoplasmic and membrane-associated Coenzyme B-Coenzyme M heterodisulfide (CoB-S-SCoM) reductase (HdrABC,HdrDE), cytochrome C and the Rhodobacter nitrogen fixation (Rnf) complex were identified and expressed, whereas genes encoding for hydrogenases were absent. Thus, ANME-2a is likely performing AOM through a complete reversal of methanogenesis from CO2 reduction without involvement of canonical hydrogenase. ANME-2a is demonstrated to possess versatile electron transfer pathways that would provide the organism with more flexibility in substrate utilization and capacity for rapid adjustment to fluctuating environments. This work lays the foundation for understanding the environmental niche differentiation, physiology and evolution of different ANME subgroups.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available