Muyzer G, Teske A, Wirsen C O, Jannasch H W
Molecular Ecology Unit, Max-Planck-Institute for Marine Microbiology, Fahrenheitstrasse 1, D-28359 Bremen, Germany.
Arch Microbiol. 1995 Sep;164(3):165-72. doi: 10.1007/BF02529967.
Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rDNA fragments was used to explore the genetic diversity of hydrothermal vent microbial communities, specifically to determine the importance of sulfur-oxidizing bacteria therein. DGGE analysis of two different hydrothermal vent samples revealed one PCR band for one sample and three PCR bands for the other sample, which probably correspond to the dominant bacterial populations in these communities. Three of the four 16S rDNA fragments were sequenced. By comparison with 16S rRNA sequences of the Ribosomal Database Project, two of the DGGE-separated fragments were assigned to the genus Thiomicrospira. To identify these 'phylotypes' in more detail, a phylogenetic framework was created by determining the nearly complete 16S rRNA gene sequence (approx. 1500 nucleotides) from three described Thiomicrospira species, viz., Tms. crunogena, Tms. pelophila, Tms. denitrificans, and from a new isolate, Thiomicrospira sp. strain MA2-6. All Thiomicrospira species except Tms. denitrificans formed a monophyletic group within the gamma subdivision of the Proteobacteria. Tms. denitrificans was assigned as a member of the epsilon subdivision and was distantly affiliated with Thiovulum, another sulfur-oxidizing bacterium. Sequences of two dominant 16S rDNA fragments obtained by DGGE analysis fell into the gamma subdivision Thiomicrospira. The sequence of one fragment was in all comparable positions identical to the 16S rRNA sequence of Tms. crunogena. Identifying a dominant molecular isolate as Tms. crunogena indicates that this species is a dominant community member of hydrothermal vent sites. Another 'phylotype' represented a new Thiomicrospira species, phylogenetically in an intermediate position between Tms. crunogena and Tms. pelophila. The third 'phylotype' was identified as a Desulfovibrio, indicating that sulfate-reducing bacteria, as sources of sulfide, may complement sulfur- and sulfide-oxidizing bacteria ecologically in these sulfide-producing hydrothermal vents.
利用聚合酶链反应（PCR）扩增的16S rDNA片段进行变性梯度凝胶电泳（DGGE），以探究热液喷口微生物群落的遗传多样性，特别是确定其中硫氧化细菌的重要性。对两个不同热液喷口样本的DGGE分析显示，一个样本有一条PCR条带，另一个样本有三条PCR条带，这可能对应于这些群落中的优势细菌种群。对四个16S rDNA片段中的三个进行了测序。通过与核糖体数据库项目的16S rRNA序列进行比较，两个经DGGE分离的片段被归为硫微螺菌属（Thiomicrospira）。为了更详细地鉴定这些“系统型”，通过测定三种已描述的硫微螺菌属物种，即嗜岩硫微螺菌（Tms. crunogena）、嗜泥硫微螺菌（Tms. pelophila）、脱氮硫微螺菌（Tms. denitrificans）以及一种新分离菌株硫微螺菌属菌株MA2 - 6的近乎完整的16S rRNA基因序列（约1500个核苷酸），构建了一个系统发育框架。除脱氮硫微螺菌外，所有硫微螺菌属物种在变形菌门γ亚纲内形成了一个单系群。脱氮硫微螺菌被归为ε亚纲的成员，并且与另一种硫氧化细菌硫螺旋菌属（Thiovulum）亲缘关系较远。通过DGGE分析获得的两个优势16S rDNA片段的序列属于γ亚纲硫微螺菌属。其中一个片段的序列在所有可比位置上与嗜岩硫微螺菌的16S rRNA序列相同。将一个优势分子分离物鉴定为嗜岩硫微螺菌，表明该物种是热液喷口位点的优势群落成员。另一个“系统型”代表了一种新的硫微螺菌属物种，在系统发育上处于嗜岩硫微螺菌和嗜泥硫微螺菌之间的中间位置。第三个“系统型”被鉴定为脱硫弧菌属（Desulfovibrio），这表明作为硫化物来源的硫酸盐还原细菌可能在这些产生硫化物的热液喷口中在生态上补充硫和硫化物氧化细菌。
