中文摘要：

[目的]分离植物乳杆菌（Lactobacillus plantarum LP101）中的质粒,并对其序列进行分析。[方法]从植物乳杆菌LP101中提取质粒并行双酶切,纯化后与载体pet22b进行连接,电转化到大肠杆菌DH5α中。将测序后得到的质粒片段进行拼接,对拼接成功的质粒进行序列分析。[结果]从植物乳杆菌LP101中分离得到一个隐蔽质粒p LP101,测序结果显示该质粒大小为3 496 bp,碱基G＋C含量为38.2%,编码了一个移动蛋白和一个复制蛋白。BLAST结果显示该质粒的核苷酸序列与干酪乳杆菌（L.casei）中的质粒p SMA23相似性在99%以上。[结论]分离得到了植物乳杆菌LP101中的一个隐蔽质粒p LP101,推定其复制方式为滾环复制,属于滚环复制p C194家族成员。

英文摘要：

[Objective]Isolation and sequence of plasmid from Lactobacillus plantarum LP101. [Methods]Plasmids were extracted from L. plantarum LP101 and determined by double digestion. The purified plasmids and pet22 b vector were ligated and transformed into host strain Escherichia coli DH5α. Fragments were spliced and analyzed after gene sequencing. [Results]A cryptic plasmid isolated from L. plantarum LP101 was sequenced and characterized. The plasmid p LP101 is a 3 496 bp circular molecule with a G ＋ C content of 38. 2%. Sequence analysis indicated that ORF1 was predicted to encode a mobilisation（ Mob） protein,and ORF2 encode a replication initiation（ Rep）. The result of BLAST showed that p LP101 shared more than99% DNA sequence identity with plasmid p LC88. [Conclusion]A cryptic plasmid has isolated from L. Plantarum LP101. According to the analysis of Rep,dso and sso,it suggested that plasmid p LP101 belongs to p C194 rolling- circle family.