乳酸菌增菌培养基的营养因子优化

以改良MRS发酵培养基为基础,选择玉米浆、牛肉膏、乳糖、番茄汁、眎蛋白胨等7个营养因子增菌培养乳酸菌进行优化。利用L8(27)正交实验,优化出培养基营养因子最佳组成是:玉米浆3%、牛肉膏1%、乳糖1%。研究结果表明,嗜酸乳杆菌、嗜热链球菌、保加利亚乳杆菌、嗜酸乳酸菌,在优化后的MRS培养基发酵液中,37℃培养20 h,菌落数均高于原MRS培养基发酵液的菌落数,达到109cfu/mL以上,乳酸菌发酵液得到了浓缩,大大降低了乳酸菌发酵培养基的成本,原料成本降低了约40%。

Optimization of the Nutrient Factors for Lactic Acid Bacteria Enrichment Medium

In the paper,we used the improved MRS as a basic medium and considering seven nutrient factors in optimizing the enrichment medium of lactic acid bacteria.The optimum nutrient factors were determined by orthogonal experiment as follows: 3% corn syrup,1% beef extract,1% lactose.The results showed that: The living-cell number of L.acidophilus,S.thremophilus,L.bulgaricus was over 109 cfu/mL,cultivating for 20 hours in the optimum MRS medium at 37℃.The production cost was decreased about 40% compared with that of using MRS medium.