乳酸肠球菌冻干保护剂的优化研究及菌粉保存效果的研究OA北大核心CSTPCD

In order to improve the survival rate of Enterococcus lactate and the preservation effect of bacterial powder in later period during vacuum freeze-drying,the single factor experiment and Box-Be-hnken design was used to screen and optimize the protective agents formula for vacuum freeze-drying of Enterococcus lactate.The results showed that the skim milk,trehalose and glycerin have the best effect,which can significantly improve the survival of Enterococcus lactate after vacuum freeze-drying.In response surface experiment of Box-Behnken,the above three protective agents were taken as independent varia-bl es,and the survival rate of cells after lyophilization was the response value.The optimized protective a-gent formula of Enterococcus lactate was obtained:skim milk 20.82％,trehalose 13％,glycerin 3％.Fur-ther verification and stability research showed that the survival rate of lyophilized thallus reached about 80.00％with the optimized protective agent formula,the lyophilized Enterococcus lactate powder can be preserved for 24 months at 4 ℃.