McDonald Ian R, Miguez Carlos B, Rogge Gerlinde, Bourque Denis, Wendlandt Karin D, Groleau Denis, Murrell J Colin
Department of Biological Sciences, University of Waikato, Hamilton, New Zealand.
FEMS Microbiol Lett. 2006 Feb;255(2):225-32. doi: 10.1111/j.1574-6968.2005.00090.x.
Methanotrophs were enriched and isolated from polluted environments in Canada and Germany. Enrichments in low copper media were designed to specifically encourage growth of soluble methane monooxygenase (sMMO) containing organisms. The 10 isolates were characterized physiologically and genetically with one type I and nine type II methanotrophs being identified. Three key genes: 16S rRNA; pmoA and mmoX, encoding for the particulate and soluble methane monooxygenases respectively, were cloned from the isolates and sequenced. Phylogenetic analysis of these sequences identified strains, which were closely related to Methylococcus capsulatus, Methylocystis sp., Methylosinus sporium and Methylosinus trichosporium. Diversity of sMMO-containing methanotrophs detected in this and previous studies was rather narrow, both genetically and physiologically, suggesting possible constraints on genetic diversity of sMMO due to essential conservation of enzyme function.
甲烷氧化菌是从加拿大和德国的污染环境中富集并分离出来的。在低铜培养基中的富集培养旨在特别促进含可溶性甲烷单加氧酶（sMMO）的生物体的生长。对这10株分离株进行了生理和遗传特征分析，鉴定出1株I型和9株II型甲烷氧化菌。分别从这些分离株中克隆并测序了三个关键基因：16S rRNA、pmoA和mmoX，它们分别编码颗粒性甲烷单加氧酶和可溶性甲烷单加氧酶。对这些序列的系统发育分析确定了与荚膜甲基球菌、甲基孢囊菌属、孢囊甲基弯曲菌和 Trichosporium甲基弯曲菌密切相关的菌株。在本研究和先前研究中检测到的含sMMO的甲烷氧化菌的多样性在遗传和生理方面都相当狭窄，这表明由于酶功能的基本保守性，sMMO的遗传多样性可能受到限制。
