利用16S rRNA序列鉴定分离自开菲尔粒的一株乳杆菌

Differentiation of Lactobacillus plantarum strain isolated from Kefir Grains by Using 16S rRNA sequence

对菌株H13的16S rRNA序列进行克隆和测序,并以此为基础构建菌株H13的系统发育树,对菌株H13进行鉴定。应用PCR技术,扩增H13菌株的16S rRNA基因,将其与pEASY-T载体相连接,用Sanger双脱氧链终止法测定序列并将16S rRNA序列与GenBank所选择的同属及非同属的菌进行同源性比较。结果表明:H13菌株16S rRNA基因序列同源性与乳杆菌属10株菌均在89%以上,与所选的植物乳杆菌和类植物乳杆菌的同源性高达99.5%和99.2%,与其他8株乳杆菌属菌株的同源性都小于97%,可进一步确定其为植物乳杆菌或类植物乳杆菌。系统发育进化树结果表明,H13与植物乳杆菌的同源性最为接近。H13最终鉴定为植物乳杆菌,该菌株现在已被中国微生物菌种保藏管理委员会普通微生物中心收录保存,编号为CGMCC 1357。

The strain H13 isolated from Kefir, which can reduce cholesterol in blood, was primarily identified as Lactococcus by physiological-biochemical characteristics. 16S rRNA gene of H13 was amplified in vitro using PCR technology and was sequenced. Compared with other ten strains of Lactococcus from GenBank, the homology of 16S rRNA gene of H13 was above 89%. Especially compared with Lactobacillus plantarum, Lactobacillus paraplantarum, the homology was even higher to 99.5%, 99.2% respectively, and lower than 97% compared with other eight strains of Lactococcus. Thus we could further identify that it was Lactobacillus plantarum or Lactobacillus paraplantarum. According to the phylogenetic tree of H13 16S rRNA gene, the homology of strain H13 was closer to Lactobacillus plantarum. In conclusion, the strain H13 belongs to Lactobacillus plantarum, and has been preserved and designated as CGMCC 1357 by China General Microbiology Culture Collection Center.