Diversity of the active methanotrophic community in acidic peatlands as assessed by mRNA and SIP-PLFA analyses
Diversity of the active methanotrophic community in acidic peatlands as assessed by mRNA and SIP-PLFA analyses
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DOI：
10.1111/j.1462-2920.2007.01466.x
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发表时间：
2008-02-01
影响因子：
5.1
通讯作者：
Murrell, J. Colin
中科院分区：
文献类型：
--
作者：
Chen, Yin;Dumont, Marc G.;Murrell, J. Colin
首次在石楠（Calluna）覆盖的高沼地和泥炭藓/Eriophorum覆盖的英国泥炭地的活跃甲烷氧化菌群落进行了调查。从这些土壤中直接提取的mRNA促进检测甲烷单加氧酶基因的表达，这表明，颗粒甲烷单加氧酶和不溶性甲烷单加氧酶可能是负责甲烷原位氧化，因为只有pmoA转录（编码亚基的颗粒甲烷单加氧酶）是容易检测。结果表明，在有胼胝体覆盖的高沼地和有泥炭藓/羊胡子草覆盖的沟壑生境中，甲烷氧化菌群落结构存在差异。与许多其他泥炭藓覆盖的泥炭地一样，泥炭藓/Eriophorum覆盖的沟壑主要由甲基囊藻属。此外，还发现了甲基壳菌属和甲基壳菌属相关种。如通过使用基于pmoA的诊断微阵列所证明的，发现了甲基杆菌相关物种。在胼胝体覆盖的高沼地，除了甲基孢菌和甲基孢囊菌外，一组独特的泥炭相关I型甲烷氧化菌后者的pmoA序列仅与Methylocapsa和甲烷氧化菌的RA-14组有较远的亲缘关系，据信它们参与大气中CH 4浓度的氧化。土壤样品也用（CH 4）-C-13标记，随后对C-13标记的磷脂脂肪酸（PLFA）的分析表明，16：1 omega 7、18：1 omega 7和18：1 omega 9是主要的标记PLFA。C-13-标记的18：1 ω 9的存在，这不是任何现存的甲烷氧化菌的主要PLFA，表明在这个泥炭地中存在新的甲烷氧化菌。
The active methanotroph community was investigated for the first time in heather (Calluna)-covered moorlands and Sphagnum/Eriophorum-covered UK peatlands. Direct extraction of mRNA from these soils facilitated detection of expression of methane monooxygenase genes, which revealed that particulate methane monooxygenase and not soluble methane monooxygenase was probably responsible for CH4 oxidation in situ, because only pmoA transcripts (encoding a subunit of particulate methane monooxygenase) were readily detectable. Differences in methanotroph community structures were observed between the Calluna-covered moorland and Sphagnum/Eriophorum-covered gully habitats. As with many other Sphagnum-covered peatlands, the Sphagnum/Eriophorum-covered gullies were dominated by Methylocystis. Methylocella and Methylocapsa-related species were also present. Methylobacter-related species were found as demonstrated by the use of a pmoA-based diagnostic microarray. In Calluna-covered moorlands, in addition to Methylocella and Methylocystis, a unique group of peat-associated type I methanotrophs (Gammaproteobacteria) and a group of uncultivated type II methanotrophs (Alphaproteobacteria) were also found. The pmoA sequences of the latter were only distantly related to Methylocapsa and also to the RA-14 group of methanotrophs, which are believed to be involved in oxidation of atmospheric concentrations of CH4. Soil samples were also labelled with (CH4)-C-13, and subsequent analysis of the C-13-labelled phospholipid fatty acids (PLFAs) showed that 16:1 omega 7, 18:1 omega 7 and 18:1 omega 9 were the major labelled PLFAs. The presence of C-13-labelled 18:1 omega 9, which was not a major PLFA of any extant methanotrophs, indicated the presence of novel methanotrophs in this peatland.