biostudies-literatureLi SGovernment of AlbertaCanada First Research Excellence FundFundamental Research Funds for the Central Universities to Muhe DiaoUniversity of CalgaryNatural Sciences and Engineering Research CouncilCanada Foundation for InnovationDiscovery Grants to Marc Strous and Bernhard Mayer, Canada Research ChairDigital Research Alliance of Canadawraf024https://www.ebi.ac.uk/biostudies/studies/S-EPMC11978286biostudies-literatureUnknown19(1)Members of Methylotenera are signature denitrifiers and methylotrophs commonly found together with methanotrophic bacteria in lakes and freshwater sediments. Here, we show that three distinct Methylotenera ecotypes were abundant in methane-rich groundwaters recharged during the Pleistocene. Just like in surface water biomes, groundwater Methylotenera often co-occurred with methane-oxidizing bacteria, even though they were generally unable to denitrify. One abundant Methylotenera ecotype expressed a pathway for aerobic methane production from methylphosphonate. This phosphate-acquisition strategy was recently found to contribute to methane production in the oligotrophic, oxic upper ocean. Gene organization, phylogeny, and 3D protein structure of the key enzyme, carbon-phosphorus lyase subunThe ISME journalProteomic evidence for aerobic methane production in groundwater by methylotrophic Methylotenera.PMC11978286CRC-2020-00257Humez PLi SMcClain CDong XStrous MBorecki JMayer BBirks JDiao MfalseProteomic evidence for aerobic methane production in groundwater by methylotrophic Methylotenera.Members of Methylotenera are signature denitrifiers and methylotrophs commonly found together with methanotrophic bacteria in lakes and freshwater sediments. Here, we show that three distinct Methylotenera ecotypes were abundant in methane-rich groundwaters recharged during the Pleistocene. Just like in surface water biomes, groundwater Methylotenera often co-occurred with methane-oxidizing bacteria, even though they were generally unable to denitrify. One abundant Methylotenera ecotype expressed a pathway for aerobic methane production from methylphosphonate. This phosphate-acquisition strategy was recently found to contribute to methane production in the oligotrophic, oxic upper ocean. Gene organization, phylogeny, and 3D protein structure of the key enzyme, carbon-phosphorus lyase subun2025-01-01T00:00:00Z2025 Jan2026-06-01T11:06:25.832Z2025-07-07T03:10:04.369ZS-EPMC119782863992798210.1093/ismejo/wraf024