Wang Yinghui, Wang Yuying, Zhou Keyu, Zhang Haili, Cheng Minggen, Wang Baozhan, Yan Xin
Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, People's Republic of China.
Jiangsu Provincial Key Lab for Solid Organic Waste Utilization, Key Lab of Organic-Based Fertilizers of China, Jiangsu Collaborative Innovation Center for Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Biotechnol Lett. 2024 Aug;46(4):713-724. doi: 10.1007/s10529-024-03495-y. Epub 2024 May 11.
Methanotrophs of the genus Methylocystis are frequently found in rice paddies. Although more than ten facultative methanotrophs have been reported since 2005, none of these strains was isolated from paddy soil. Here, a facultative methane-oxidizing bacterium, Methylocystis iwaonis SD4, was isolated and characterized from rhizosphere samples of rice plants in Nanjing, China. This strain grew well on methane or methanol but was able to grow slowly using acetate or ethanol. Moreover, strain SD4 showed sustained growth at low concentrations of methane (100 and 500 ppmv). M. iwaonis SD4 could utilize diverse nitrogen sources, including nitrate, urea, ammonium as well as dinitrogen. Strain SD4 possessed genes encoding both the particulate methane monooxygenase and the soluble methane monooxygenase. Simple and rapid genetic manipulation methods were established for this strain, enabling vector transformation and unmarked genetic manipulation. Fast growth rate and efficient genetic tools make M. iwaonis SD4 an ideal model to study facultative methanotrophs, and the ability to grow on low concentration of methane implies its potential in methane removal.
甲基孢囊菌属的甲烷营养菌在稻田中很常见。自2005年以来，虽然已报道了十多种兼性甲烷营养菌，但这些菌株均未从稻田土壤中分离得到。在此，从中国南京水稻植株的根际样品中分离并鉴定了一株兼性甲烷氧化细菌——岩沼甲基孢囊菌SD4。该菌株在甲烷或甲醇上生长良好，但也能够利用乙酸盐或乙醇缓慢生长。此外，SD4菌株在低浓度甲烷（100和500 ppmv）下表现出持续生长。岩沼甲基孢囊菌SD4能够利用多种氮源，包括硝酸盐、尿素、铵以及氮气。SD4菌株拥有编码颗粒状甲烷单加氧酶和可溶性甲烷单加氧酶的基因。为该菌株建立了简单快速的遗传操作方法，实现了载体转化和无标记遗传操作。快速的生长速率和高效的遗传工具使岩沼甲基孢囊菌SD4成为研究兼性甲烷营养菌的理想模型，其在低浓度甲烷上生长的能力意味着它在甲烷去除方面具有潜力。
