甲烷氧化菌

甲烷氧化菌(英語:Methanotroph)又稱嗜甲烷菌,泛指可以分解甲烷,將其作為碳源與能源的細菌古菌,可能為嗜氧或厭氧菌,通常生長在濕地、沼澤、湖泊或海洋等會產生甲烷的環境,但也有些可利用大氣中的甲烷。甲烷氧化菌為甲基营养菌英语Methylotroph(泛指使用甲烷、甲醇甲醛等單碳化合物為碳源的細菌)的一個子類別,有些甲基营养菌除單碳化合物外,還可使用多碳化合物為碳源,但大多數甲烷氧化菌屬苛求性細菌英语Fastidious organism,僅能使用甲烷一種碳源,Methylocella silvestris英语Methylocella silvestris[1][2]Methylocapsa aurea英语Methylocapsa aurea[3]甲基孢囊菌屬的數種細菌為例外[4],這些細菌屬兼性甲烷氧化菌,除甲烷外尚能使用一些小分子有機物為碳源。甲烷氧化菌因可消耗甲烷而為全球暖化的研究者所關注[5][6]

有些化學自營的硝化細菌氧化作為能源,以二氧化碳為碳源,在氧化氨的過程中可能將周圍環境的甲烷一起氧化,為對其代謝無顯著影響的副反應,此類細菌一般不被視為甲烷氧化菌[6]

氧化過程

RuMP途徑
絲氨酸途徑

甲烷氧化菌氧化甲烷的過程,通常會先以甲烷單氧化酶英语methane monooxygenase(MMOs)將甲烷氧化成甲醇,再氧化為甲醛,然後經絲氨酸途徑或RuMP途徑合成有機物[7]

參見

參考文獻

  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.