嗜酸乳杆菌NX2-6冻干发酵剂的研究

Study on freeze- drying protective agents formula of Lactobacillus acidophilus NX2-6

为制备嗜酸乳杆菌NX2-6高活性发酵剂,研究了其高密度发酵后真空冷冻干燥时不同冷冻保护剂对其存活率的影响。通过离心条件的选择,获得了最大浓度的嗜酸乳杆菌NX2-6。进而采用单因素实验和正交实验设计,以冻干后的菌体存活率为指标,考察了10种冻干保护剂对嗜酸乳杆菌NX2-6冷冻干燥的保护效果,以获得对嗜酸乳杆菌NX2-6真空冷冻干燥的最佳保护剂配方。实验结果表明,嗜酸乳杆菌NX2-6在8000r/min的条件下离心10min(4℃),所得的活菌数最多。实验确定嗜酸乳杆菌NX2-6的最佳保护剂配方为以15%麦芽浸粉,3%谷氨酸钠和7%菊糖作为复合保护剂,在此条件下嗜酸乳杆菌NX2-6的冻干存活率高达82.43%。

For the preparation of Directed Vat Set （DVS）of Lactobacillus acidophilus NX2-6, the effect of different protective agents on the survival rate of Lactobacillus acidophilus NX2-6 during the vacuum freeze-drying was investigated.Influences of centrifugation conditions on the survival rate of Lactobacillus acidophilus NX2-6 was first examined.Then single-factor experiments and orthogonal experiments were carried out to obtain the optimum protective agents formula according to the survival rate of Lactobacillus acidophilus NX2-6 after vacuum freeze- drying.The results showed that most optimum centrifugation conditions for preparing the suspension were 8000r/min and ;Omin（at 4℃）.The optimal protective agent formula for Lactobacillus acidophilus NX2-6 were as following ： malt extract powder 15%, sodium glutamate 3% and inulin 7%. Using this protective agent formula, the survival rate of Lactobacillus acidophilus NX2-6 after vacuum freeze-drying was up to 82.43%.