动物双歧杆菌RH胞外多糖基因簇的克隆及分析

Cloning and Bioinformatics Analysis of Exopolysaccharide Biosynthsis from Bifidobacterium animalis subsp. lactis RH

利用16S rRNA结合tuf基因将一株分离自广西巴马长寿老人源的产胞外多糖菌株RH鉴定为动物双歧杆菌乳亚种(Bifidobacterium animalis subsp.lactis RH),根据GenBank中已报道动物双歧杆菌乳亚种产糖相关基因设计引物,经PCR扩增获得双歧杆菌RH的12个胞外多糖(EPS)生物合成相关基因。对各阅读框功能预测分析表明这些基因主要参与EPS合成过程多糖聚合、糖基转移、糖链长度控制以及多糖转运和输出,为解析双歧杆菌RH胞外多糖生物合成途径和调控机制提供理论基础。

Bifidobacterium has been accepted as an important probiotic bacterium with its health benefit on the host, its exopolysaccharides （EPS） also have antioxidant and immune modulating function for humans. In this work, we identified an exopolysaccharide producing strain as Bifidobacterium animalis subsp, lactis RH by physiological, biochemical, 16S rRNA and tufanalysis. The specific primers of wzx, wzy, wzz and so on were designed according to the conservative gene sequences of Bifidobacterium animalis subsp, lactis AD011 from GenBank. And we acquired 12 gene sequences such as repeat unit transporter（Wzx） and repeat unit polymerase（Wzy）. Functional prediction analysis of open reading frames （ORF） indicates that these 12 genes encode the amino acid sequences of the proteins involved in polysaccharide chain length determination, polymerization and transport. The results of this research may lay a foundation for further understanding of the EPS biosynthetic pathway of Bifidobacterium and the underlying mechanism.