植物乳杆菌及其近缘种部分看家基因的系统发育分析

Phylogenetic Analysis of Lactobacillus plantarum and Related Species Using Partial Housekeeping Genes

摘要:

本文研究了16S rRNA基因、pheS和pyrG部分基因序列对Lactobacillus plantarum（L. plantarum）及其近缘种的区分能力，采用分离自酸面团、酸牛奶和泡菜中的10株L. plantarum为研究对象，以其看家基因pheS和pyrG部分基因序列作为分子标记，结合已上传至GeneBank的近缘种的相应序列构建系统发育树并与以16S rRNA基因构建的系统发育树进行比较。结果表明：基于16S rRNA基因序列不能区分L. plantarum及其近缘种，而看家基因pheS和pyrG部分基因序列能够很好的区分植物乳杆菌种及其近缘种，其中，pheS在植物乳杆菌种内分型时相较于pyrG基因效果更好，以及将pheS和pyrG部分基因序列串联使用后，试验菌株与参考菌株的分类关系更加明晰，因此，联合基因（pheS-pyrG）可作为16S rRNA基因的辅助工具用于L. plantarum及近缘种和植物乳杆菌种内分型的快速分类鉴定。

Abstract:

Phylogenetic trees of L. plantarum strains were constructed to explore the usage of the 16S rRNA gene, pheS and pyrG gene sequences for distinguishing Lactobacillus plantarum from its related species.. The phylogenetic trees of ten L. plantarum strains isolated from sourdough, yoghurt, and pickles were constructed using partial sequences of housekeeping genes, pheS and pyrG, as molecular markers. These trees were compared with other phylogenetic trees constructed using the 16S rRNA gene sequence of L. plantarum combined with the corresponding gene sequences of closely related strains already published in GenBank. The results showed that L. plantarum and its related species could be distinguished by analyzing the 16S rRNA gene sequence; however, pheS and pyrG sequences could be used for this classification. Additionally, it was found that sequential use of pheS and pyrG could clearly distinguish strains from reference strains. Thus, a combination of genes (pheS-pyrG) could be used as an auxiliary tool along with 16S rRNA gene analysis for rapid classification and identification of L. plantarum and related species.