益生菌D-1液体发酵工艺的研究

Fermentation technology of probiotic strain D-1

为提高菌体的得率和芽孢转化率,进行了菌株D1最佳培养条件参数和培养基优化的研究及测定此条件下的生长曲线。通过研究发酵温度、接种量、培养基初始pH、溶解氧等因素对菌株D1生长的影响,确定最佳培养条件为:培养温度30℃,培养基初始pH7.0,接种量5%(相对摇瓶装液量),装液量100mL/500mL。在发酵基础培养基成分保持不变的情况下改变氮源、碳源、生长因子、无机盐单因子进行单因子试验,采用L9(3)4正交表设计实验,进行培养基优化,确定最佳培养基配比为玉米淀粉2%,蛋白胨2.5%,NaH2PO40.8%,玉米浆1.5%,MgSO4·7H2O0.05%,3.08%MnSO4水溶液0.1%。在最佳培养条件下,用最优培养基测定了菌株D1的生长曲线,并确定了菌株D1的最佳种龄为18～20h,生产收获时间为26h。

In order to increase bacteria production and ratio of spore formation, experiments were conducted to obtain the best fermentation condition and media, and to determine the growth curve under the most favourable culture. The most favourable fermantation for strain D-1 was 30℃ in temperature, 6.5 -6.8 in initial of media pH, 5% inoculum size, and 100 mL media per 500 mL flask in volume. Suitable culture medium was obtained through testing the single effect of medium elements on growth of D-1, including carbon sources, nitrogen sources, inorganic salt and growth factor. The optimal prescription for D-1 fermentation, as determined by orthogonal testing, was composed of 2% maize starch, 2. 5% peptone, 0. 8% NaH2PO4, 1.5% maize syrup, 0. 05% MgSO4·7H2O and 0. 1% MnSO4 （3.08%） . To obtain the best inoculate and culture time, the growth curve of D-1 was determined under the most favourable medium and culture conditioris. As determined from the growth curve, the best inoculate time should be 18 -20 h, and culture time should be 26 h.