一株植物乳杆菌的分离鉴定及其隐蔽质粒的序列分析

Isolation and Identification of a Lactobacillus plantarum Strain and Sequence Analysis of Its Cryptic Plasmid

从传统发酵乳制品中分离到1株乳酸杆菌,经API50CH细菌鉴定系统和16SrRNA基因序列分析后鉴定为植物乳杆菌。分析该菌的质粒图谱后发现该菌携带多个质粒,将其中的小质粒pLD1测序,结果显示该质粒的大小为2112bp,碱基G+C含量为37.8%,只编码1个复制蛋白,其中有1个17bp的序列重复了13次。BLAST发现该质粒同pLP2000等的同源性在95%以上,其中复制蛋白同其他质粒存在一些氨基酸差异。pLD1质粒序列的GenBank登陆号为NC_012220,并且它可用于构建良好的乳杆菌基因工程载体。

A strain isolated from traditionally fermented dairy product was identified as Lactobacillus plantarum based on API 50 CH bacteria identification system and 16S rRNA sequence analysis.Plasmid profile indicated that this strain harbored several plasmids.A small plasmid designated as pLD1 was subjected to sequence analysis.This small plasmid had 2112 bp and G＋C content of 37.8%.Meanwhile,a sequence with 17 bp was repeated 13 times in this small plasmid.BLAST results showed that pLD1 plasmid had more than 95% similarity with pLP2000 and that there was a difference in replication protein among this plasmid and others.The accession number of this small plasmid is NC_012220 and it is useful for the construction of genetically engineered vectors.