双歧杆菌与嗜热链球菌混菌培养研究

研究了短双歧杆菌（Ｂｉｆｉｄｏｂａｃｔｅｒｉｕｍｂｒｅｖｅ）和嗜热链球菌（Ｓｔｒｅｐｔｏｃｏｃｃｕｓｔｈｅｒｍｏｐｈｉｈｕｓ）的选择性培养条件，探讨了两菌在单一菌种培养和混菌培养状况下的菌体生长和产酸特点，发现该两菌种之间的生长及产酸存在着明显的互相促进作用，在牛乳培养基中混菌培养状况下两菌的生长及产酸代谢均优于单菌种培养．在两菌的接种量体积分数各为１％的条件下，不但能获得较高的活菌数，而且凝乳状态及风味都比较好．

Studies on Mixed cultuer of Bifidobacterium breve and Streptococcus thermophilus

Selective culture conditions of Bifidobacterium breve and Streptococcus thermophilus were studied and the characteristics of biomass proliferation and acid production metabolism,by pure and mixed culture in milk medium,were discussed.It was found that in TPY medium containing 25ug/mL kanamycin sulfate,B breve 4 2 2 could grow very well but S thermophilus 29 could not grow under the anaerobic condition.On the contrary,the result was reversed when these organisms were seperately cultured in cysteine identification medium under the aerobic condition.Thus,the conditions described above were used as the selective culture conditions,after mixed culture,for counting cells of both strains respectively.Under the condition with the same inoculum,organisms proliferation of mixed culture is much better than that of pure culture.Studies on acid production metabolism showed that acid production in mixed culture was higher than that of single culture,and stimulation of producing acid existed between B breve and S thermophilus.In addition,milk curd state and flavour are perfect in mixed culture.