Reverse Methanogenesis and Respiration in Methanotrophic Archaea

Reverse Methanogenesis and Respiration in Methanotrophic Archaea

Timmers, Peer H.A. (Wageningen University & Research; Wetsus, Centre for Sustainable Water Technology; Soehngen Institute of Anaerobic Microbiology)
Welte, Cornelia U. (Soehngen Institute of Anaerobic Microbiology; Radboud Universiteit Nijmegen)
Koehorst, Jasper J. (Wageningen University & Research)
Plugge, Caroline M. (Wageningen University & Research; Wetsus, Centre for Sustainable Water Technology)
Jetten, M.S.M. (TU Delft BT/Environmental Biotechnology; Soehngen Institute of Anaerobic Microbiology; Radboud Universiteit Nijmegen)
Stams, Alfons J M (Wageningen University & Research; Soehngen Institute of Anaerobic Microbiology; University of Minho)

2017

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.

http://resolver.tudelft.nl/uuid:c8623f8c-e99b-472c-a5da-951f450ae091

https://doi.org/10.1155/2017/1654237

1472-3646

Archaea, 2017

Institutional Repository

review

© 2017 Peer H.A. Timmers, Cornelia U. Welte, Jasper J. Koehorst, Caroline M. Plugge, M.S.M. Jetten, Alfons J M Stams