乳双歧杆菌U9冷冻保护剂的优化研究

Screening and Optimization of the Freeze Protectants for Bifidobacterium animalis subsp.lactis U9

乳双歧杆菌U9是一株具有优良益生功能的乳杆菌。为了保证U9菌株活性,为工业化益生菌制剂生产提供稳定菌种,利用液氮深冷方式对U9菌株进行冷冻保藏。以冷冻存活率为评价指标,对冷冻保护剂种类进行筛选,并对保护剂配方进行正交试验优化。结果表明,甘油、海藻糖、脱脂乳粉及维生素C 4种保护剂能对乳双歧杆菌U9起到良好的保护作用;正交试验优化确定的保护剂配方为甘油2%、海藻糖7.5%、脱脂乳粉7.5%、维生素C 0.1%,菌体冷冻后存活率达到94%。

To improve the preparation technology of probiotic in industrial production, the liquid nitrogen cryogenic treatment was used in the preparation of Bifidobacterium animalis subsp, lactis U9 starter. The optimal formula of freeze protectants was 2% glcerol, 7.5% trehalose, 7.5% skim milk powder, and 0.1% Vitamin C （ m ： m ） , which was determined by screening different kinds of freeze protectant by single-factor experiments and optimizing the concentrations of preferred freeze protectants by orthogonal test. The survival rate of Bifidobacterium animalis subsp, lactis U9 was 94% after freezing with optimal freeze protectants.