Skip to Main content Skip to Navigation
Journal articles

Nitrite-driven anaerobic methane oxidation by oxygenic bacteria

Abstract : Only three biological pathways are known to produce oxygen: photosynthesis, chlorate respiration and the detoxification of reactive oxygen species. Here we present evidence for a fourth pathway, possibly of considerable geochemical and evolutionary importance. The pathway was discovered after metagenomic sequencing of an enrichment culture that couples anaerobic oxidation of methane with the reduction of nitrite to dinitrogen. The complete genome of the dominant bacterium, named 'Candidatus Methylomirabilis oxyfera', was assembled. This apparently anaerobic, denitrifying bacterium encoded, transcribed and expressed the well-established aerobic pathway for methane oxidation, whereas it lacked known genes for dinitrogen production. Subsequent isotopic labelling indicated that 'M. oxyfera' bypassed the denitrification intermediate nitrous oxide by the conversion of two nitric oxide molecules to dinitrogen and oxygen, which was used to oxidize methane. These results extend our understanding of hydrocarbon degradation under anoxic conditions and explain the biochemical mechanism of a poorly understood freshwater methane sink. Because nitrogen oxides were already present on early Earth, our finding opens up the possibility that oxygen was available to microbial metabolism before the evolution of oxygenic photosynthesis
Document type :
Journal articles
Complete list of metadatas

Cited literature [51 references]  Display  Hide  Download

https://hal-cea.archives-ouvertes.fr/cea-00907649
Contributor : Bruno Savelli <>
Submitted on : Tuesday, October 15, 2019 - 10:49:28 AM
Last modification on : Wednesday, June 17, 2020 - 3:42:03 PM
Long-term archiving on: : Friday, January 17, 2020 - 8:11:19 AM

File

Ett.pdf
Publisher files allowed on an open archive

Identifiers

Collections

Citation

Katharina F. Ettwig, Margaret K. Butler, Denis Le Paslier, Eric Pelletier, Sophie Mangenot, et al.. Nitrite-driven anaerobic methane oxidation by oxygenic bacteria. Nature, Nature Publishing Group, 2010, 464 (7288), pp.543-548. ⟨10.1038/nature08883⟩. ⟨cea-00907649⟩

Share

Metrics

Record views

389

Files downloads

654