我国新疆地区传统酸马奶中乳酸菌资源丰富，为获得高效降解乳糖的乳酸菌及其发酵条件，本实验从分离自新疆酸马奶的14 株乳酸菌中，筛选出1 株高效水解乳糖的发酵乳杆菌RB-6，其乳糖水解率达37%。进一步利用单因素试验和正交试验对发酵乳杆菌RB-6的发酵温度、接种量和发酵时间进行优化，获得其乳糖水解率最高的发酵条件为：发酵温度39 ℃、接种量3%、发酵时间8 h。发酵乳杆菌RB-6在该条件下发酵酸奶的乳糖水解率达47%，比优化前提高了10%。

Koumiss, a traditional fermented mare’s milk in Xinjiang province of China, is an abundant source of lactic acid
bacteria. Fourteen strains of lactic acid bacteria from Koumiss were screened for lactose-hydrolyzing ability. A strain of
Lactobacillus fermentum RB-6 with high rate of lactose hydrolysis (37%) was obtained. Single-factor and orthogonal array
designs were used to optimize the inoculum quantity, fermentation temperature, and fermentation time for the selected
strain. The results indicated that when the fermentation was carried out for 8 h with an inoculum size of 3% at 39 ℃, the rate
of lactose hydrolysis was 47%, which was increased by 10% as compared with that before optimization.