基于末端产物和基因序列的SRB菌系统发育分析

为实现细菌的多相分类,应用Hungate厌氧技术,从大庆油田采出液中分离到8株硫酸盐还原菌.通过对菌株的气相色谱末端产物测定,16S rDNA、16S～23S rDNA间隔区(ISR)序列克隆进行菌株的系统发育分析.结果表明:8株菌分别属于Salmonella(D2、I7)、Clostridium(F4、D10、H1)、Anaerofilum(A8、A18)、Enterobacter(E1).聚类分析表明,菌株的ISR序列长度差异较大,包含的tRNA种类和数目不同,间隔区序列可以作为16S rDNA序列系统发育分类的一个有力的补充;气相色谱末端产物相似的菌株,亲源关系比较接近,可以作为细菌鉴定的依据;其中16S rDNA序列作为细菌分类的主要依据,对存在争议的菌株,应该结合形态、生理生化特征和ISR序列以及气相色谱末端产物等综合对其进行系统分类.

Phylogenetic analysis of sulfate reducing bacteria based on terminal products and sequence genes

Applying the Hungate anaerobic technology,8 strains of sulfate reducing bacteria (SRB) were isolated from the wastewater of Daqing Oilfield. Terminal products were analyzed by gas chromatography and the sequence cloning of 16S-23S rDNA intergenic spacer region was used for the phylogenetic analysis of sulfate reducing bacteria. The results show that 8 strains of SRB belong to Salmonella D2 and Salmonella I7,Clostridium F4,Clostridium D10 and Clostridium H1,Anaerofilum A8 and Anaerofilum A18,and Enterobacter E1. The analysis of clustering shows that the length diversity for the intergenic spacer region sequence of 16S-23S rDNA is large,and the variety and quantity of tRNA are distinct. The 16S-23S rDNA intergenic spacer region can be used as an effective supplement of 16S rRNA sequence phylogenetic analysis. Terminal products of the strains detected by gas chromatography are similar and exhibit close phylogenetic relationship. It can be seen as the foundation of identification,and the sequence of 16S rDNA is the main foundation of classification. For stains in dispute,the phylogenetic analysis on them should be according to the morphological,physiological and biochemical characteristics,16S-23S rDNA intergenic spacer region sequence,and the analysis of terminal products by gas chromatography.