四川牦牛奶和曲拉中九株乳酸菌的分子鉴定

摘要

为准确鉴定分离自我国四川鲜牦牛奶和曲拉中9株乳酸茵到种水平,作者运用16S rDNA 序列分析、recA基因特异扩增和hsp60- RFLP等多种分子技术对分离自我国四川地区鲜牦牛奶和曲拉中的9株乳酸茵进行分类鉴定.结果证实,16S rDNA序列分析法可将9株乳酸茵初步归类为植物乳杆菌群(4株),肠膜明串珠菌(4株),瑞士乳杆菌(1株).由于16S rDNA序列分析法不能区分植物乳杆菌和戊糖乳杆菌,为了进一步鉴定植物乳杆菌群中的4株茵,继续采用recA基因特异扩增和hsp60-RFLP技术对其细分,结果表明recA基因特异扩增和hsp60-RFLP 的方法均能很好地把植物乳杆菌群中的4株茵鉴定到种水平,且均为植物乳杆菌.%In this study, To accurately identify lactic acid bacteria (LAB) that were isolated from fresh yak milk and Qula in Sichuan region of China, nine LAB strains were classified and identified to species level by using 16S rDNA sequencing analysis, multiplex PCR assay of recA gene, hsp60-PCR-RFLP analysis etc. The results showed that nine LAB strains were initially characterized as Lactobacillus plantarum group (4 strains), Leuconostoc mesenteroides (4 strains) and Lactobacillus helveticus (1 strain) by 16S rDNA sequencing analysis. However, 16S rDNA sequencing analysis could not distinguish between L. plantarum and L. pentosus. For further identification of strains in L. plantarum group, multiplex PCR assay of recA gene and hsp60-RFLP analysis were conducted. The results revealed that multiplex PCR assay of recA gene and hsp60-RFLP could identify L. plantarum group to species level and 4 LAB strains in L. plantarum group were identified as L. plantarum.