细菌型豆豉发酵菌株的鉴定

Identification of starter culture for bacteria douchi

为了明确细菌型豆豉发酵菌株的身份,首先采用形态及生理生化方法进行鉴定,接着提取该菌株的基因组DNA,并根据芽孢杆菌属16S rDNA序列两端的保守性片段设计引物,然后用PCR方法扩增出16S rDNA部分序列,纯化、测序,最后经BLAST搜索进行序列比对和构建系统进化树。结果表明,菌株BBDC3为革兰氏阳性芽孢杆菌,生理生化特征与枯草芽孢杆菌相符;扩增出的16S rDNA部分序列长为1344bp,与序列号为EF488171的枯草芽孢杆菌16S rDNA序列的相似度最高,为99%;系统进化树中,菌株BBDC3与枯草芽孢杆菌AB018487在同一分支。因此,菌株BBDC3属于枯草芽孢杆菌。

To make certain of the identity of starter culture for bacteria douchi, the strain was identified first by morphological, physiological and biochemical methods.Then the genomic DNA of this strain was extracted and the primer was designed according to conserved fragments at both ends of the genus Bacillus 16S rDNA sequence. Next the 16S rDNA partial sequence was amplified by PCR method followed by purified and sequenced.Finally, sequence alignment was done by BLAST searching and the phylogenetic tree was constructed.Results showed that strain BBDC3 was Gram positive and endospore-forming rod.The physiological and biochemical characters of strain BBDC3 were the same as those of Bacillus subtilis.The length of 16S rDNA partial sequence amplified was 1344bp and the 16S rDNA sequence similarity between strain BBDC3 and Bacillus subtilis EF488171 was highest at 99%.1n the phylogenetic tree,strain BBDC3 and Bacillus subtilis AB018487 were in the same branch.Accordingly, strain BBDC3 belonged to Bacillus subtilis.