Filamentous "Epsilonproteobacteria" dominate microbial mats from sulfidic cave springs
Filamentous "Epsilonproteobacteria" dominate microbial mats from sulfidic cave springs
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DOI：
10.1128/aem.69.9.5503-5511.2003
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发表时间：
2003-09-01
影响因子：
4.4
通讯作者：
Wagner, M
中科院分区：
文献类型：
--
作者：
Engel, AS;Lee, N;Wagner, M
富含硫化氢的地下水从泉水排入怀俄明州下凯恩洞穴，在那里发现了以丝状形态为主的微生物垫。全周期 rRNA 方法，包括 16S rRNA 基因检索和荧光原位杂交 (FISH)，用于鉴定这些丝。从垫子中获得的大部分 16S rRNA 基因克隆属于“ε变形菌”，并在该类中形成两个不同的簇，称为 LKC 组 I 和 LKC 组 II。第一组与来自受石油污染的地下水、硫化泉和硫化洞穴的未培养环境克隆密切相关（97%至99%的序列相似性），而第二组形成了一个与深海热液喷口共生体中度相关的新分支（90%至94%的序列相似性）。使用新设计的探针对两组微生物进行 FISH 特异性染色垫内的丝状细菌。对下凯恩洞穴 (Lower Kane Cave) 六个不同微生物垫样本中的两个丝状体群进行基于 FISH 的定量显示，LKC II 类群在六个微生物垫群落中占主导地位。这项研究进一步拓展了我们对极端环境中“ε变形菌”多样性和地理分布的认识，并证明了它们在地下生态系统中的生物地球化学重要性。
Hydrogen sulfide-rich groundwater discharges from springs into Lower Kane Cave, Wyoming, where microbial mats dominated by filamentous morphotypes are found. The full-cycle rRNA approach, including 16S rRNA gene retrieval and fluorescence in situ hybridization (FISH), was used to identify these filaments. The majority of the obtained 16S rRNA gene clones from the mats were affiliated with the "Epsilonproteobacteria" and formed two distinct clusters, designated LKC group I and LKC group II, within this class. Group I was closely related to uncultured environmental clones from petroleum-contaminated groundwater, sulfidic springs, and sulfidic caves (97 to 99% sequence similarity), while group II formed a novel clade moderately related to deep-sea hydrothermal vent symbionts (90 to 94% sequence similarity). FISH with newly designed probes for both groups specifically stained filamentous bacteria within the mats. FISH-based quantification of the two filament groups in six different microbial mat samples from Lower Kane Cave showed that LKC group II dominated five of the six mat communities. This study further expands our perceptions of the diversity and geographic distribution of "Epsilonproteobacteria" in extreme environments and demonstrates their biogeochemical importance in subterranean ecosystems.