title: Nitrate- and nitrite-dependent anaerobic oxidation of methane.
abstract: Microbial methane oxidation is an important process to reduce the emission of the greenhouse gas methane. Anaerobic microorganisms couple the oxidation of methane to the reduction of sulfate, nitrate and nitrite, and possibly oxidized iron and manganese minerals. In this article, we review the recent finding of the intriguing nitrate- and nitrite-dependent anaerobic oxidation of methane (AOM). Nitrate-dependent AOM is catalyzed by anaerobic archaea belonging to the ANME-2d clade closely related to Methanosarcina methanogens. They were named 'Candidatus Methanoperedens nitroreducens' and use reverse methanogenesis with the key enzyme methyl-coenzyme M (methyl-CoM) reductase for methane activation. Their major end product is nitrite which can be taken up by nitrite-dependent methanotrophs. Nitrite-dependent AOM is performed by the NC10 bacterium 'Candidatus Methylomirabilis oxyfera' that probably utilizes an intra-aerobic pathway through the dismutation of NO to N2and O2for aerobic methane activation by methane monooxygenase, yet being a strictly anaerobic microbe. Environmental distribution, physiological and biochemical aspects are discussed in this article as well as the cooperation of the microorganisms involved.
authors.affiliation: Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.|Soehngen Institute of Anaerobic Microbiology, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.
authors.forename: Cornelia U
authors.initials: CU
authors.lastname: Welte
authors.affiliation: Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.|Netherlands Earth Systems Science Center, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.
authors.forename: Olivia
authors.initials: O
authors.lastname: Rasigraf
authors.affiliation: Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.
authors.forename: Annika
authors.initials: A
authors.lastname: Vaksmaa
authors.affiliation: Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.
authors.forename: Wouter
authors.initials: W
authors.lastname: Versantvoort
authors.affiliation: Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.
authors.forename: Arslan
authors.initials: A
authors.lastname: Arshad
authors.affiliation: Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.
authors.forename: Huub J M
authors.initials: HJ
authors.lastname: Op den Camp
authors.affiliation: Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.|Soehngen Institute of Anaerobic Microbiology, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.|Netherlands Earth Systems Science Center, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.
authors.forename: Mike S M
authors.initials: MS
authors.lastname: Jetten
authors.affiliation: Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.
authors.forename: Claudia
authors.initials: C
authors.lastname: Lüke
authors.affiliation: Department of Microbiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, Nijmegen, AJ, 6525, The Netherlands.
authors.forename: Joachim
authors.initials: J
authors.lastname: Reimann
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D008697:Methane / Q000378:metabolism*; D019640:Methanosarcinales / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D009566:Nitrates; D009573:Nitrites; D008697:Methane