东太平洋海隆深海热液区沉积物微生物多样性的研究

Bacterial diversity of hydrothermal fluid ecosystem on the east Pacific Ocean ridge

提取东太平洋海隆区深海热液系统沉积物样品的总DNA,构建沉积物中的细菌16S rDNA克隆文库,通过PCR-RFLP分析与序列测定,对沉积物中的微生物类群及其与环境的关系进行了分析.结果表明,该海区沉积物中的36个克隆代表的22种基因型分别属于7个主要类群,其中变形菌(Proteobacteria)的γ-亚群为优势菌群,α-和β-亚群也均有分布;而硫氧化相关共生菌的属(sul-fur-oxidizing symbionts)为优势种属.系统发育分析表明,在该沉积物中细菌主要是跟共生有关、跟C、S代谢相关,大多还能在无氧和高温环境的条件下生存,说明采样点具有典型的深海热液生态系统的特点,甲烷代谢和硫代谢在该区域的深海物质能量循环中占据着重要地位.另外大量新的极端微生物的存在,预示着该区域的微生物资源有着非常大的开发潜力.

The environmental DNA was directly extracted from the sediment of hydrothermal vent field, on the east Pacific Ocean ridge. Bacterial 16S rRNA gene library was generated using bacterial universal primers and 16S rDNA sequences were analyzed phylogenetically after RFLP analysis. Twenty-two phylotypes from 36 clones were found belonging to 7 Phyla, respectively. Among them, class γ-proteobacteria of Phylum proteobacteria was the dominant with the present of α-proteobacteria and β-proteobacteria. The preponderant genus is sulfur-oxidizing symbionts. Phy- logenetic analysis showed that bacteria in sediment were related to metabolism of carbon and sulfur,which are very important for the cycle of material and energy in deep-sea, and they survive under the anaerobic and high tem pera- ture conditions characteristic of hydrothermal activity. Moreover, the abundance of new extremephiles indicates that the bacterial resources of this site are of high potential for further exploitation.