干酪乳杆菌LC-1高密度培养基优化

Optimization of high-density culture medium of lactobacillus casei LC-1 strain

为提高其发酵液的生物量,研究所用分离自甘肃甘南藏区牧民自制传统酸乳的干酪乳杆菌LC-1。以MRS培养基为基础,通过单因素试验私正交试验优化了培养基配方,确定了碳源、氮源、磷源、微量元素、缓冲盐的添加量。最终得到的优化培养基配方为：葡萄糖18g、牛肉粉11g、胰蛋白胨11g、酵母粉5.5g、K_2HPO_4 3g、无水乙酸钠3g、柠檬酸氢二铵1.5 g、MgSO_4·7H_2O0.5g、MnSO_4·H_2O 0.3g、吐温-801 mL。使用优化后的MRS培养基比基MRS培养基培养所得的活菌数提高了1个数量级,活菌数可达5.8×10~9 cfu/mL,OD值提高了1.3倍。

Lactobacillus casei LC-1 strain used in this study were isolated from traditional homemade yogurt of Gansu Gannan Tibetan herdsmen.In order to improve the biomass of the fermented liquid,on the basis of MRS medium,through single factor test and orthogonal test to optimize the medium formula,the paper finally determined the amount of carbon source,nitrogen source,phosphorus source,trace elements,buffer salt.The final optimum medium formula was glucose 18 g,beef powder 11 g,tryptone 11 g,yeast 5.5 g,KH_2PO_4 3 g,sodium acetateanhydrous 3g,ammonium citrate dibasic 1.5 g,MgSO_4·7H_2O 0.5g,MnSO_4·H_2O 0.3 g,tween-801 mL.The number of live bacteria produced by optimized MRS medium is increased 1 orders than basis MRS medium,with the number of live bacteria reaching 5.8×10~9 cfu/mL and the OD value increasing 1.3 times.