利用16S rDNA结合gyrA和gyrB基因对生防芽孢杆菌R31的快速鉴定

Use of 16S rDNA,gyrA and gyrB Gene Sequence to Identify a Biocontrol Bacillus sp. Strain R31

克隆16S rDNA、DNA促旋酶A亚基编码基因gyrA和B亚基编码基因gyrB对分离自石斛兰(Dendrobiumsp.)叶片的广谱抗真菌生防芽孢杆菌R31进行鉴定。首先通过生理生化测定和克隆16S rDNA序列,分析显示其属于芽孢杆菌属(Bacillus),但不能准确鉴定到种;然后分别利用克隆的gyrA基因和gyrB基因以及其BLAST分析结果构建系统发育树,最终将该菌株确定为枯草芽孢杆菌(B.subtilis)。结果显示利用16S rDNA与gyrA基因组合可以快速鉴定枯草芽孢杆菌,利用16S rDNA与gyrB基因组合可以快速鉴定枯草芽孢杆菌及其近缘种。

BLAST analysis based on 16S rDNA sequence gave information that strain R31 was a strain of Bacillus.Even combined with the information about physiological and biochemical characteristics,the exact species could not be identified.Furthermore,gyrA gene and gyrB gene,which encode the subunit A and B of DNA gyrase,respectively,were cloned and used to identify the strain R31.Phylogenetic tree based on the BLAST results with gyrA gene sequence or gyrB gene sequence could identify strain R31 as B.subtilis.Combination of 16S rDNA and gyrA gene sequence could be used to identify B.subtilis,while the 16S rDNA and gyrB gene sequence could be used to identify closely related taxa species in B.subtilis group.