Methanotroph

Methanotrophs (sometimes called methanophiles) are prokaryotes that metabolize methane as their source of carbon and chemical energy. They are bacteria or archaea, can grow aerobically or anaerobically, and require single-carbon compounds to survive.

Methanotrophs are especially common in or near environments where methane is produced, although some methanotrophs can oxidize atmospheric methane. Their habitats include wetlands, soils, marshes, rice paddies, landfills, aquatic systems (lakes, oceans, streams) and more. They are of special interest to researchers studying global warming, as they play a significant role in the global methane budget, by reducing the amount of methane emitted to the atmosphere.[1][2]

Methanotrophy is a special case of methylotrophy, using single-carbon compounds that are more reduced than carbon dioxide. Some methylotrophs, however, can also make use of multi-carbon compounds; this differentiates them from methanotrophs, which are usually fastidious methane and methanol oxidizers. The only facultative methanotrophs isolated to date are members of the genus Methylocella silvestris,[3][4] Methylocapsa aurea[5] and several Methylocystis strains.[6]

In functional terms, methanotrophs are referred to as methane-oxidizing bacteria. However, methane-oxidizing bacteria encompass other organisms that are not regarded as sole methanotrophs. For this reason, methane-oxidizing bacteria have been separated into subgroups: methane-assimilating bacteria (MAB) groups, the methanotrophs, and autotrophic ammonia-oxidizing bacteria (AAOB), which cooxidize methane.[2]

  1. ^ Oremland RS, Culbertson CW (1992). "Importance of methane-oxidizing bacteria in the methane budget as revealed by the use of a specific inhibitor". Nature. 356 (6368): 421–423. Bibcode:1992Natur.356..421O. doi:10.1038/356421a0. S2CID 4234351.
  2. ^ a b Holmes AJ, Roslev P, McDonald IR, Iversen N, Henriksen K, Murrell JC (August 1999). "Characterization of methanotrophic bacterial populations in soils showing atmospheric methane uptake". Applied and Environmental Microbiology. 65 (8): 3312–8. Bibcode:1999ApEnM..65.3312H. doi:10.1128/AEM.65.8.3312-3318.1999. PMC 91497. PMID 10427012.
  3. ^ Dedysh SN, Knief C, Dunfield PF (July 2005). "Methylocella species are facultatively methanotrophic". Journal of Bacteriology. 187 (13): 4665–70. doi:10.1128/JB.187.13.4665-4670.2005. PMC 1151763. PMID 15968078.
  4. ^ Chen Y, Crombie A, Rahman MT, Dedysh SN, Liesack W, Stott MB, et al. (July 2010). "Complete genome sequence of the aerobic facultative methanotroph Methylocella silvestris BL2". Journal of Bacteriology. 192 (14): 3840–1. doi:10.1128/JB.00506-10. PMC 2897342. PMID 20472789.
  5. ^ Dunfield PF, Belova SE, Vorob'ev AV, Cornish SL, Dedysh SN (November 2010). "Methylocapsa aurea sp. nov., a facultative methanotroph possessing a particulate methane monooxygenase, and emended description of the genus Methylocapsa". International Journal of Systematic and Evolutionary Microbiology. 60 (Pt 11): 2659–2664. doi:10.1099/ijs.0.020149-0. PMID 20061505.
  6. ^ Belova SE, Baani M, Suzina NE, Bodelier PL, Liesack W, Dedysh SN (February 2011). "Acetate utilization as a survival strategy of peat-inhabiting Methylocystis spp". Environmental Microbiology Reports. 3 (1): 36–46. Bibcode:2011EnvMR...3...36B. doi:10.1111/j.1758-2229.2010.00180.x. PMID 23761229.