对干酪乳杆菌群(Lactobacillus casei group)内5个种和4个亚种的23个代表菌株的苯丙氨酰-tRNA合成酶α亚基基因(pheS)序列和18个16S rRNA基因序列进行系统发育学分析,探索pheS基因序列分析在干酪乳杆菌群种水平鉴定中应用的可行性。分析结果表明,pheS基因序列群内种间的差异率在6.8%～34%之间,种内最大差异率可达3%,其变异率远高于16S rRNA基因,可作为该群内种水平鉴定的重要手段。

The phenylalanyl-tRNA synthase alpha subunit(pheS) gene sequences and 16S rRNA gene sequences of representative strains of 5 species and 4 subspecies from Lactobacillus casei group were analyzed by phylogenic method.The feasibility of the pheS gene sequences for species identification of the Lactobacillus casei group was studied.Results showed that the interspecies divergence of pheS gene sequences was between 6.8%~34% and the highest intra-species divergence could reach 3%.The discriminatory power of pheS gene sequences was higher than that of 16S rRNA gene sequences,the pheS gene sequences analysis could be an important tool in species identification in the Lactobacillus casei group.