甲烷氧化菌

甲烷氧化菌(英语:Methanotroph)又称嗜甲烷菌,泛指可以分解甲烷,将其作为碳源与能源的细菌古菌,可能为嗜氧或厌氧菌,通常生长在湿地、沼泽、湖泊或海洋等会产生甲烷的环境,但也有些可利用大气中的甲烷。甲烷氧化菌为甲基营养菌英语Methylotroph(泛指使用甲烷、甲醇甲醛等单碳化合物为碳源的细菌)的一个子类别,有些甲基营养菌除单碳化合物外,还可使用多碳化合物为碳源,但大多数甲烷氧化菌属苛求性细菌英语Fastidious organism,仅能使用甲烷一种碳源,Methylocella silvestris英语Methylocella silvestris[1][2]Methylocapsa aurea英语Methylocapsa aurea[3]甲基孢囊菌属的数种细菌为例外[4],这些细菌属兼性甲烷氧化菌,除甲烷外尚能使用一些小分子有机物为碳源。甲烷氧化菌因可消耗甲烷而为全球暖化的研究者所关注[5][6]

有些化学自营的硝化细菌氧化作为能源,以二氧化碳为碳源,在氧化氨的过程中可能将周围环境的甲烷一起氧化,为对其代谢无显著影响的副反应,此类细菌一般不被视为甲烷氧化菌[6]

氧化过程

RuMP途径
丝氨酸途径

甲烷氧化菌氧化甲烷的过程,通常会先以甲烷单氧化酶英语methane monooxygenase(MMOs)将甲烷氧化成甲醇,再氧化为甲醛,然后经丝氨酸途径或RuMP途径合成有机物[7]

参见

参考文献

  1. ^ Dedysh SN, Knief C, Dunfield PF. Methylocella species are facultatively methanotrophic. Journal of Bacteriology. July 2005, 187 (13): 4665–70. PMC 1151763 . PMID 15968078. doi:10.1128/JB.187.13.4665-4670.2005. 
  2. ^ Chen Y, Crombie A, Rahman MT, Dedysh SN, Liesack W, Stott MB, et al. Complete genome sequence of the aerobic facultative methanotroph Methylocella silvestris BL2. Journal of Bacteriology. July 2010, 192 (14): 3840–1. PMC 2897342 . PMID 20472789. doi:10.1128/JB.00506-10. 
  3. ^ Dunfield PF, Belova SE, Vorob'ev AV, Cornish SL, Dedysh SN. 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. November 2010, 60 (Pt 11): 2659–2664. PMID 20061505. doi:10.1099/ijs.0.020149-0 . 
  4. ^ Belova SE, Baani M, Suzina NE, Bodelier PL, Liesack W, Dedysh SN. Acetate utilization as a survival strategy of peat-inhabiting Methylocystis spp. Environmental Microbiology Reports. February 2011, 3 (1): 36–46. PMID 23761229. doi:10.1111/j.1758-2229.2010.00180.x. 
  5. ^ Oremland RS, Culbertson CW. Importance of methane-oxidizing bacteria in the methane budget as revealed by the use of a specific inhibitor. Nature. 1992, 356 (6368): 421–423. Bibcode:1992Natur.356..421O. S2CID 4234351. doi:10.1038/356421a0. 
  6. ^ 6.0 6.1 Holmes AJ, Roslev P, McDonald IR, Iversen N, Henriksen K, Murrell JC. Characterization of methanotrophic bacterial populations in soils showing atmospheric methane uptake. Applied and Environmental Microbiology. August 1999, 65 (8): 3312–8. Bibcode:1999ApEnM..65.3312H. PMC 91497 . PMID 10427012. doi:10.1128/AEM.65.8.3312-3318.1999. 
  7. ^ Hanson RS, Hanson TE. Methanotrophic bacteria. Microbiological Reviews. June 1996, 60 (2): 439–71. PMC 239451 . PMID 8801441. doi:10.1128/MMBR.60.2.439-471.1996.