Several formula of seed mediums were compared, milk+20% tomato juice+2%extractions from Jerusalem artichoke can accelerate to produce acid, attain higher Bifidobacterium Longum number.

• 脱脂乳+20%25番茄汁+2%25菊芋抽提液作为种子培养基产酸速度快，双歧杆菌活菌数高。