动物双歧杆菌冻干保护剂配方优化及酸对菌粉存活率的影响

Formulation optimization of lyophilized protective agent for Bifidobacterium animalis and its effect on the survival rate of bacterial powder

中文关键词:  动物双歧杆菌  冷冻干燥  存活率  保护剂优化

英文关键词:Bifidobacteria animalis  freeze-dried  survival rate  protective agent optimization

中文摘要:

      目的 筛选动物双歧杆菌冻干菌粉保护剂, 优化冻干保护剂配方, 探究菌悬液制备过程中有机酸积累对菌粉存活率的影响。方法 以菌粉中动物双歧杆菌存活率为指标, 通过发酵培养、离心收集菌泥、制备菌悬液、预冻和冷冻干燥的菌粉制备工艺, 通过单因素实验和正交实验优化冻干保护剂。根据单因素实验探究冻干前菌悬液制备条件和最适pH。结果 最佳保护剂组合为5.00%麦芽糊精、6.00%海藻糖、0.15%抗坏血酸、1.50%谷氨酸钠、1.00%甘油。通过对菌悬液制备过程中菌粉活菌数的研究确定菌悬液制备和冻干条件, 菌悬液pH 6.5, 无菌水洗涤2次菌, 4℃菌悬液融合30 min, 在-80℃预冻2 h, ?40℃下干燥24 h, 获得的冻干菌粉活菌数为1.38×1012 CFU/g, 菌粉最高存活率可达98.60%。结论 本研究优化后的保护剂组合可以制备高活性动物双歧杆菌菌粉, 提高经济效益。

英文摘要:

      Objective To screen the protective agent of freeze-dried powder of Bifidobacterium animalis, optimize the formula of freeze-dried protective agent, and explore the influence of organic acid accumulation on the survival rate of powder during the preparation of bacterial suspension. Methods The survival rate of Bifidobacterium animalis in bacterial powder was taken as the index, and the lyophilized protectant was optimized by single-factor test and orthogonal test by fermentation culture, centrifugation collection of bacterial sludge, preparation of bacterial suspension, pre-freezing and freeze-drying of bacterial powder. According to the single-factor test, the preparation conditions and optimal pH of the freeze-dried prebacterial suspension were explored. Results The best combination of protective agents was 5.00% maltodextrin, 6.00% trehalose, 0.15% ascorbic acid, 0.15% sodium glutamate, and 1.00% glycerol, and the preparation conditions and lyophilization conditions of bacterial suspension were determined by studying the number of viable bacteria of acid to bacterial powder during the preparation of bacterial suspension, the pH of the bacterial suspension was 6.5, the bacterial sludge was washed twice with sterile water, the bacterial suspension was fused for 30 min at 4℃, prefrozen at ?80℃ for 2 h, dried at ?40℃ for 24 h, and the viable bacteria number of lyophilized bacterial powder was 1.38×1012 CFU/g. The highest survival rate of bacterial powder could reach 98.60%. Conclusion The optimized combination of protective agents in this study can prepare high-activity Bifidobacterium animalis powder and improve economic benefits.