一株芽孢杆菌16SrRNA的基因序列测定和系统进化分析

Sequencing and phylogenetic analysis of the partial 16S rRNA in a Bacillus strain

从河南黄河稻区土壤中分离出一株具有较强稻瘟病菌拮抗活性的芽孢杆菌菌株BS501,经过形态观察、生理生化特性检测和电镜技术,确定其为芽孢杆菌属细菌。为进一步确定其分类学地位,扩增了BS501基因组的16S rDNA,并将测序结果提交GenBank数据库(登录号:FJ755787)。利用BLAST软件将该序列与枯草芽孢杆菌、地衣芽孢杆菌等芽孢菌属细菌及大肠杆菌16S rDNA序列进行同源性比对。系统进化树表明,BS501与芽孢菌属细菌在进化关系上组成一个大的分支,与枯草芽孢杆菌最为接近,与大肠杆菌较远。同源性分析表明该序列与枯草芽孢杆菌PRE23同源性达99%,证实该菌株的分类学地位为枯草芽孢杆菌。

A Bacillus strain BS501 which had strong antagonistic activity of M.grisea was isolated from the soil of rice field near the Yellow river in Henan.BS501 was determined to be a Bacillus bacteria through morphological observation,physiological and biochemical characterization and electronic microscopy.To further determine the taxonomic status of the strain,the 16S rDNA of BS501genome was amplified,and the sequencing result was submitted to the GenBank database（GenBank accession number is FJ755787）.The homology of 16S rDNA sequence of BS501 and Bacillus subtilis,Bacillus licheniformis,other Bacillus spp,and E.coli was compared using BLAST software.The phylogenetic tree showed that BS501 and Bacillus spp bacteria form a large branch in the evolution of relations,and BS501 was the closest to Bacillus subtilis,and was the fartherest to E.coli.Homologous analysis showed that the sequence homology of BS501 and Bacillus subtilis PRE23 was 99%.The result confirmed that the taxonomic status of strain BS501 is Bacillus subtilis.