乳酸克鲁维酵母与乳酸菌混菌发酵对乳糖降解条件的优化

摘要

In order to optimize the lactose degradation conditions by mixed fermentation from Kluyveromyces Lactis and Lactobacillus bulgaricus and Streptococcus thermophilus,Three factors influenced the lactose degradation rate were studied,including inoculum density of Kluyveromyces Lactis,fermentation temperature,fermentation time,and orthogonal test was used to optimize the parameters.Direct colorimetric method was used for the determination of lactose content.The result showed that the optimum conditions of lactose degradation by mixed fermentation were inoculum density ofKluyveromyces Lactis 5log cfu·mL-1,fermentation temperature 30 ℃,fermentation time 6.5 h.Under the above conditions,the average lactose degradation rate was 25.45％.%为优化乳酸克鲁维酵母与德氏乳杆菌保加利亚亚种及嗜热链球菌混菌发酵降解乳糖的条件,研究了乳酸克鲁维酵母的接种量、发酵温度和发酵时间3个因素对乳糖降解率的影响,并采用正交试验优化参数.利用直接比色法测定乳糖质量浓度.结果表明,最佳混菌发酵降解乳糖的条件为乳酸克鲁维酵母的接种量5.5 mL-1(对数值),发酵温度32℃,发酵时间5.5 h.此条件平均乳糖降解率为25.45％.