Molecular diversity of methanotrophs in Transbaikal soda lake sediments and identification of potentially active populations by stable isotope probing.
Molecular diversity of methanotrophs in Transbaikal soda lake sediments and identification of potentially active populations by stable isotope probing.
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DOI：
10.1111/j.1462-2920.2004.00635.x
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发表时间：
2004-10
影响因子：
5.1
通讯作者：
Ju-Ling Lin;S. Radajewski;B. Eshinimaev;Y. Trotsenko;I. McDonald;J. Murrell
中科院分区：
文献类型：
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作者：
Ju-Ling Lin;S. Radajewski;B. Eshinimaev;Y. Trotsenko;I. McDonald;J. Murrell
苏打湖是一种pH值异常高、盐度通常也很高的环境。为了鉴定Soda湖沉积物中的活性甲烷氧化菌，将沉积物浆液在10% (v/v) (13)CH(4)顶空气中孵育，然后通过CsCl密度梯度离心从这些沉积物中提取（13）c标记的DNA。然后将该DNA作为模板进行16S rRNA基因和甲烷氧化途径关键酶甲烷单加氧酶PmoA和MmoX基因的PCR扩增。对16S rRNA基因、PmoA和MmoX的系统发育分析发现，甲基微生物、甲基杆菌、甲基单胞菌和甲基热菌都吸收了（13）CH(4)。稳定同位素探测（SIP）处理前提取的DNA扩增的PmoA序列系统发育分析表明，该碱性环境中存在更广泛的I型和II型甲烷化菌序列多样性。（13）C-DNA研究中检测到的大多数甲烷化菌序列来自I型甲烷化菌，其中50%的16S rRNA克隆和100%的pmoA克隆来自Suduntuiskii Torom湖和Gorbunka湖，这表明I型甲烷化菌可能是该环境中大部分甲烷氧化的原因。
Soda lakes are an environment with an unusually high pH and often high salinity. To identify the active methanotrophs in the Soda lake sediments, sediment slurries were incubated with a 10% (v/v) (13)CH(4) headspace and the (13)C-labelled DNA was subsequently extracted from these sediments following CsCl density gradient centrifugation. This DNA was then used as a template for PCR amplification of 16S rRNA genes and genes encoding PmoA and MmoX of methane monooxygenase, key enzymes in the methane oxidation pathway. Phylogenetic analysis of 16S rRNA genes, PmoA and MmoX identified that strains of Methylomicrobium, Methylobacter, Methylomonas and 'Methylothermus' had assimilated the (13)CH(4). Phylogenetic analysis of PmoA sequences amplified from DNA extracted from Soda lake sediments before Stable Isotope Probing (SIP) treatment showed that a much wider diversity of both type I and type II methanotroph sequences are present in this alkaline environment. The majority of methanotroph sequences detected in the (13)C-DNA studies were from type I methanotrophs, with 50% of 16S rRNA clones and 100% of pmoA clones from both Lake Suduntuiskii Torom and Lake Gorbunka suggesting that the type I methanotrophs are probably responsible for the majority of methane oxidation in this environment.