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Reverse Methanogenesis and Respiration in Methanotrophic Archaea.
- Source :
-
Archaea (Vancouver, B.C.) [Archaea] 2017 Jan 05; Vol. 2017, pp. 1654237. Date of Electronic Publication: 2017 Jan 05 (Print Publication: 2017). - Publication Year :
- 2017
-
Abstract
- Anaerobic oxidation of methane (AOM) is catalyzed by anaerobic methane-oxidizing archaea (ANME) via a reverse and modified methanogenesis pathway. Methanogens can also reverse the methanogenesis pathway to oxidize methane, but only during net methane production (i.e., "trace methane oxidation"). In turn, ANME can produce methane, but only during net methane oxidation (i.e., enzymatic back flux). Net AOM is exergonic when coupled to an external electron acceptor such as sulfate (ANME-1, ANME-2abc, and ANME-3), nitrate (ANME-2d), or metal (oxides). In this review, the reversibility of the methanogenesis pathway and essential differences between ANME and methanogens are described by combining published information with domain based (meta)genome comparison of archaeal methanotrophs and selected archaea. These differences include abundances and special structure of methyl coenzyme M reductase and of multiheme cytochromes and the presence of menaquinones or methanophenazines. ANME-2a and ANME-2d can use electron acceptors other than sulfate or nitrate for AOM, respectively. Environmental studies suggest that ANME-2d are also involved in sulfate-dependent AOM. ANME-1 seem to use a different mechanism for disposal of electrons and possibly are less versatile in electron acceptors use than ANME-2. Future research will shed light on the molecular basis of reversal of the methanogenic pathway and electron transfer in different ANME types.<br />Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper.
- Subjects :
- Anaerobiosis
Oxidation-Reduction
Archaea metabolism
Methane metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1472-3654
- Volume :
- 2017
- Database :
- MEDLINE
- Journal :
- Archaea (Vancouver, B.C.)
- Publication Type :
- Academic Journal
- Accession number :
- 28154498
- Full Text :
- https://doi.org/10.1155/2017/1654237