正交法厌氧优化分离乳酸菌及凝固型酸奶的研制

初步建立一种较简单而有效从市售酸奶中分离乳酸菌来发酵酸奶的分离方法，采用MRS乳酸菌选择性培养基培养．经革兰染色、葡萄糖产酸、接触酶和石蕊牛奶试验分离鉴定出乳酸菌．以正交法优化厌氧培养采用L9（3^3）正交试验，得出最佳葡萄糖、蔗糖和维生素B2组合的改良MRS配方（葡萄糖8％，蔗糖1．5％，维生素B20．005％），并用来活化、扩大培养菌种，发酵凝固型酸奶．

Lactobacteria Isolated by Orthogonal Design Method in Anaerobic Incubation and Applied to Solidifying Yogurt

To optimize the condition of separating method,this study used MRS selective culture medium to separate the lactic acid bacteria with a series of experiments from Hui Shan and Kang Xian brands yoghurt respectively.To culture without aeration using L9(33)design of experiments research into the best way of improved MRS,and the result showed that:glucose 8%,sucrose 1.5%,vitamin B2 0.005%.Then using the activated bacteria and the extended cultivation to ferment set yoghure from Hui Shan fresh milk and sugar.