Diversity and distribution of methanotrophic archaea at cold seeps
Diversity and distribution of methanotrophic archaea at cold seeps
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DOI：
10.1128/aem.71.1.467-479.2005
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发表时间：
2005-01-01
影响因子：
4.4
通讯作者：
Amann, R
中科院分区：
文献类型：
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作者：
Knittel, K;Lösekann, T;Amann, R
在这项研究中，我们用基于16S rRNA的方法研究了(I)水合物山脊(俄勒冈州卡斯卡迪亚边缘)露头甲烷水合物上方的沉积物和(Ii)包围碳酸盐礁(克里米亚地区，黑海)的大量微生物垫中古细菌的分布和生物量。这两个地点的古生物多样性都很低；只有4个(水合物岭)和5个(黑海)不同的系统发育序列簇，其中大部分属于甲烷营养古菌(ANME)。ANME组2(ANME-2)层序是水合物海脊最丰富、最多样的层序，而ANME-1层序在黑海席地中占主导地位。其他SEEP特异序列属于新定义的ANME-3组(与甲烷球菌属相关)。通过荧光原位杂交(FISH)定量分析表明，ANME-1和ANME-2在所调查的冷渗点同时存在。在水合岭，表层沉积物主要由ANME-2和Desuffiosarcina/DSS分支(DSS)成员组成的聚集体(ANME-2/DSS聚集体)组成，占总细胞生物量的90%。ANME-1细胞的数量随深度的增加而显著增加，占表层单个细胞总数的1%，占天然气水合物正上方7~10 cm沉积层中单个细胞总数的30%以上。在黑海，微生物垫ANME-1约占所有细胞的50%。ANME-2/DSS聚集体存在于垫子内的微环境中，但仅占细胞总数的1%。基于比较的16S rRNA分析，设计了ANME-2a和ANME-2c亚簇的FISH探针。在水合物岭沉积物中，ANME-2a/DSS和ANME-2c/DSS聚集体在形态和丰度上存在明显差异。各亚群在Beggiatoa站点(80%ANME-2a，20%ANME-2c)和Calytogena站点(20%ANME-2a，80%ANME-2c)的相对丰度值存在显著差异，表明这两种生境存在种群的优先选择。根据微生物生态型的存在、生态位的形成和生物地理，讨论了甲烷营养联合体的分布、多样性和形态的这些变化。
In this study we investigated by using 16S rRNA-based methods the distribution and biomass of archaea in samples from (i) sediments above outcropping methane hydrate at Hydrate Ridge (Cascadia margin off Oregon) and (ii) massive microbial mats enclosing carbonate reefs (Crimea area, Black Sea). The archaeal diversity was low in both locations; there were only four (Hydrate Ridge) and five (Black Sea) different phylogenetic clusters of sequences, most of which belonged to the methanotrophic archaea (ANME). ANME group 2 (ANME-2) sequences were the most abundant and diverse sequences at Hydrate Ridge, whereas ANME-1 sequences dominated the Black Sea mats. Other seep-specific sequences belonged to the newly defined group ANME-3 (related to Methanococcoides spp.) and to the Crenarchaeota of marine benthic group B. Quantitative analysis of the samples by fluorescence in situ hybridization (FISH) showed that ANME-1 and ANME-2 co-occurred at the cold seep sites investigated. At Hydrate Ridge the surface sediments were dominated by aggregates consisting of ANME-2 and members of the Desuffiosarcina-Desulfococcus branch (DSS) (ANME-2/DSS aggregates), which accounted for >90% of the total cell biomass. The numbers of ANME-1 cells increased strongly with depth; these cells accounted 1% of all single cells at the surface and more than 30% of all single cells (5% of the total cells) in 7- to 10-cm sediment horizons that were directly above layers of gas hydrate. In the Black Sea microbial mats ANME-1 accounted for about 50% of all cells. ANME-2/DSS aggregates occurred in microenviromments within the mat but accounted for only 1% of the total cells. FISH probes for the ANME-2a and ANME-2c subclusters were designed based on a comparative 16S rRNA analysis. In Hydrate Ridge sediments ANME-2a/DSS and ANME-2c/DSS aggregates differed significantly in morphology and abundance. The relative abundance values for these subgroups were remarkably different at Beggiatoa sites (80% ANME-2a, 20% ANME-2c) and Calyptogena sites (20% ANME-2a, 80% ANME-2c), indicating that there was preferential selection of the groups in the two habitats. These variations in the distribution, diversity, and morphology of methanotrophic consortia are discussed with respect to the presence of microbial ecotypes, niche formation, and biogeography.