Moosvi S Azra, McDonald Ian R, Pearce David A, Kelly Donovan P, Wood Ann P
Department of Life Sciences, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
Syst Appl Microbiol. 2005 Aug;28(6):541-54. doi: 10.1016/j.syapm.2005.03.002.
This study is the first demonstration that a diverse facultatively methylotrophic microbiota exists in some Antarctic locations. PCR amplification of genes diagnostic for methylotrophs was carried out with bacterial DNA isolated from 14 soil and sediment samples from ten locations on Signy Island, South Orkney Islands, Antarctica. Genes encoding the mxaF of methanol dehydrogenase, the fdxA for Afipia ferredoxin, the msmA of methanesulfonate monooxygenase, and the 16S rRNA gene of Methylobacterium were detected in all samples tested. The mxaF gene sequences corresponded to those of Hyphomicrobium, Methylobacterium, and Methylomonas. Over 30 pure cultures of methylotrophs were isolated on methanesulfonate, dimethylsulfone, or dimethylsulfide from ten Signy Island lakes. Some were identified from 16S rRNA gene sequences (and morphology) as Hyphomicrobium species, strains of Afipia felis, and a methylotrophic Flavobacterium strain. Antarctic environments thus contain diverse methylotrophic bacteria, growing on various C1-substrates, including C1-sulfur compounds.
本研究首次证明，在南极的一些地区存在多种兼性甲基营养微生物群落。利用从南极南奥克尼群岛西格尼岛10个地点采集的14份土壤和沉积物样本中分离得到的细菌DNA，对甲基营养菌的诊断基因进行了PCR扩增。在所有测试样本中均检测到编码甲醇脱氢酶mxaF、阿菲彼亚铁氧化还原蛋白fdxA、甲磺酸单加氧酶msmA的基因以及甲基杆菌的16S rRNA基因。mxaF基因序列与生丝微菌属、甲基杆菌属和甲基单胞菌属的序列相对应。从西格尼岛的10个湖泊中，以甲磺酸、二甲基砜或二甲基硫为培养基，分离出30多种甲基营养菌的纯培养物。其中一些根据16S rRNA基因序列（以及形态）被鉴定为生丝微菌属物种、阿菲彼亚猫菌株和一种甲基营养黄杆菌菌株。因此，南极环境中含有多种甲基营养细菌，它们以各种C1底物为生长源，包括C1硫化合物。
