一株产细菌素乳酸菌的分离与鉴定

目的]对从新疆和田地区酸奶中分离得到的1株具有抑菌活性的菌株A3-1,分别进行形态观察、生理生化试验及16S rDNA鉴定。方法]采用真细菌16S rDNA通用引物PCR扩增A3-1菌株的16S rDNA,使用NCBI-Blast软件在GenBank数据库中对其进行同源性检索,使用MEGA4软件构建系统发育树。结果]A3-1为革兰氏阳性菌,并且对大肠杆菌和金黄色葡萄球菌的生长有明显的抑制作用;其16S rDNA与Leuconostoc lactis有98.829%的同源性。结论]系统发育树表明菌株A3-1与乳酸明串珠菌亲缘关系最近,结合生理生化分析,可判断菌株为乳酸明串珠菌。

Isolation and Identification of A Acid Bacterium A3-1 for Bacteriocin Acid Production

Objective ] Strain A3-I with bacteriostatic activity was isolated from yoghurt in Hotan Region, the morphological observation, physiological and biochemical experiments, and 16SrDNA identification were conducted. Method] The common primers for the 16SrDNA of eubacteria were used for polymerase chain reaction. Homology analysis was made by searching in Genbank with NCBI-Blast and the phylogenet- ic tree was constructed with MEGA4. Result] Strain A3-1 is gram positive bacteria, and has obvious inhibition to the growth of Escherichia coli and Staphylococcus aureus. And its 16SrDNA has 98. 829% homology with Leuconostoc lactis. Conclusion~ The tree showed the closest relationship was between strain A3-1 and Leuconostoc lactis. Combined with physiological and biochemical analysis, strain A3-1 can be judged as Leuconostoc lactis.