为了筛选益生乳酸菌，从传统发酵乳制品之发酵剂开菲尔粒中分离到一株优势菌株，命名为HUCM 201，经形态学特征、16S rDNA基因序列及生理生化特性分析，将其鉴定为乳酸乳球菌乳亚种（Lactococcus lactis subsp. lactis）。该菌株对酸和胆汁均表现出了一定的耐受能力，在模拟人工胃液的环境中培养3 h后，活菌数接近于105 CFU/mL水平；而经1%牛胆汁作用4 h后，活菌数仅出现了微弱的减少。同时，以Caco-2细胞为模型模拟肠道上皮细胞检测细菌的黏附能力，菌株HUCM 201对Caco-2细胞表现出了一定的黏附性，黏附率为1.93%。通过最低抑制浓度法（MICs）评价了其对抗生素的敏感性，发现其对氨苄青霉素、万古霉素、红霉素、氯霉素、青霉素5种常见抗生素均敏感。乳酸乳球菌乳亚种HUCM 201可作为一株潜在的优良候选菌株进行深入研究。

In order to select probiotic, lactic acid bacteria, a predominant strain, named HUCM 201, was isolated from Kefir grains, which is used as a starter culture for traditional fermented dairy products. This bacterial strain was identified as Lactococcuslactis subsp. Lactis based on its morphologic properties, 16S rDNA sequences, as well as physiological and biochemical characteristics. The strain showed a certain degree of tolerance to acid and bile. After 3 h in a simulated gastric fluid, viable counts for the strain were maintained up to 105 CFU/mL. HUCM 201 strain exposed to MRS broth supplemented with 1% oxgall for 4 h showed a slight decrease in cell viability. Meanwhile, Caco-2 cells, a model forintestinal epithelial cells, were used to measure bacterial adhesive ability. HUCM 201 strain exhibited adherence to Caco-2 cells with an adhesion ratio of1.93%. The minimum inhibitory concentration was used to evaluate antibiotic susceptibility of the isolate. This strain was found to be susceptible to ampicillin, vancomycin, erythromycin, chloramphenicol, and penicillin. Thus Lactococcuslactis subsp. lactisstrain HUCM 201 is a good candidate for further investigation.

黑龙江中医药大学校科研基金项目（201104）；黑龙江省教育厅面上项目（12531631）