甘肃牧区传统发酵乳制品中优良乳酸菌的分离筛选

从甘肃牧区传统发酵乳制品中分离筛选适合发酵乳生产的乳酸菌，对分离纯化的乳酸菌进行了发酵性能检测，筛选出产酸快、发酵活力高、凝乳时间短、后酸化能力弱、遗传性状稳定的菌株。筛选的6株菌株单菌发酵牛乳，均在6.5 h内凝乳，发酵乳酸度＞70 °T，乳酸菌活菌数＞1×108 CFU/mL，发酵乳组织状态、滋味、气味等感官指标良好，可作为生产发酵乳的优良乳酸菌菌种进行开发利用。

Isolation and screening of excellent lactic acid bacteria from traditional fermented dairy products in Gansu pastoral area

The lactic acid bacteria suitable for fermented milk production from traditional fermented dairy products in Gansu pastoral area were isolated and screened, and their fermentation performances were detected. The lactic acid bacteria screened had fast acid production rate, high fermentation activity, short curd time, weak postacidification ability and stable inheritable character. The six strains of lactic acid bacteria were screened. The fermented milks by six individual strain were all curded within 6.5 h, the acidity of fermented milk was more than 70 °T, the viable counts of lactic acid bacteria were more than 1×108 CFU/ml. The sensory indexes (including texture, taste, smell, etc) of fermented milk were good. The six strains could be used as excellent lactic acid bacteria for producing fermented milk to be developed and utilized.