保加利亚乳杆菌菌粉生产工艺研究

Study for production process of Lactobacillus bulgaricus powder

通过对保加利亚乳杆菌NQ-2508菌株的培养基、培养条件、生产工艺、冷冻干燥保护剂及保存条件进行研究,结果表明:发酵培养基MRS中主要物质最佳组合为葡萄糖2%+酪蛋白胨1%+牛肉浸膏1%+酵母粉0.5%,最佳生长温度为37℃,发酵终点pH值为4.70～4.80。冷冻干燥保护剂最佳组合为海藻糖10%+蔗糖8%+L-半胱氨酸1%+谷氨酸钠1%,通过菌粉生产中试,获得了活菌数达到5.0×1010cfu/g以上的冻干菌粉。并确定该菌粉适宜在低温条件下保存,为直投式酸奶发酵剂产业化生产打下了基础。

In this paper we study the optimal media, growth condition, product process, lyophilized protective and preservation condition for Lactobacillus bulgaricus NQ-2508, and determined the optimum combination of main compositions in MRS broth by orthogonal design is 2%（w/v） glucose, 1%（w/v） casein peptone, 1%（w/v） beef extract, 0.5%（w/v） yeast extract. We also determined the optimal growth temperature of NQ-2508 is 37 ℃ and terminal pH of 4.70-4.80, the optimal combination of freeze-drying protective agent is 10%（w/v） trehalose, 8% （w/v） sucrose, 1% （w/v）L-cysteine, 1% （w/v） sodium glutamate. We obtained the powder of lyophilized Lactobacillus bulgaricus through production pilot scale test and viable cell count was above 5.0×10^10 cfu/g, and determined the proper preservation condition was low temperature. This study laid a foundation of commercial production of freeze drying yoghurt starter.