酸奶发酵剂增殖条件的初步研究

为优化乳酸菌增殖培养基配方。通过正交筛选试验研究了在MRS基础培养基中添加不同营养物质对乳酸菌生长的影响。结果表明：往液体MRS基础培养基中添加1%的胡萝卜汁、1.5%的麦芽汁和0.5%的大豆汁配成增殖培养基，增殖培养10 h后，每隔2 h添加1%的KH2PO4-Na2HPO4缓冲剂(pH 6.86)，培养16 h后，乳酸菌活菌数为3.94×109 cfu/mL，比优化前提高了11.6%。为进一步开展营养强化因子筛选打下了基础。

Study on the Culture Method for the Multiplication of Lactobacillus in Cultures for Yoghurt

In order to obtain the proliferation medium of streptococcus thermophilus and Lactobacillus bulgaricus,on the basis of MRS medium added different nutrients to the influence of lactic acid bacteria growth,and further optimized by orthogonal test screening.The results showed that the appropriate growth conditions were determined as：improved MRS as basic medium,with an addition of 1% carrot juice,1.5% wort,0.5% soybean juice,KH 2 PO 4-Na 2 HPO 4（pH 6.86） solution was spiked into the mash with a 2 h interval after 10 h fermentation at 42-45℃,and cultured for 16 h,the number of viable cells of lactic acid bacteria 3.94×10 9 cfu/mL,increased 11.6 percent higher than before.The effect of lactic acid bacteria proliferation was not satisfactory,needed to continue to explore effective nutritional enhancement factor.