枯草芽孢杆菌发酵条件的优化及微生态制剂的研制

Optimization of Bacillus subtilis fermentation conditions and preparation of its microecological probiotics

以从海参肠道中筛选的枯草芽孢杆菌为发酵菌株，通过单因素实验和正交实验确定了发酵培养基的最佳成分，即葡萄糖1.0％、牛肉膏1.5％、K2HPO40.5％；最适发酵条件为发酵温度30℃，初始pH7.2，接种量4％，发酵时间38～40h。经过优化后发酵液的活茵浓度可达到3.98×10^9 cfu／mL。再以1％海藻酸钠为壁材，4％氯化钙作为固化剂，将发酵后收集的菌体通过乳化法和挤压法制成微胶囊制剂，采用活菌计数法进行该微胶囊制剂的稳定性实验。结果显示，分别采用乳化法和挤压法包埋制备的微胶囊制剂的活菌存活率均高于未经微胶囊化的样品，但乳化法制备工艺相对较为简单且微胶囊形成速度较快，因此预计乳化法将更适合于该菌株微生态制剂的大规模工业化生产。

This study focused on optimization of Bacillus subtilis fermentation conditions and preparation of its microecological probiotics.With single factor trial and orthogonal experiment,the optimal fermentation liquid media were determined as glucose 1.0%, beef extract 1.5% and K2HPO4 0.5%. The optimal fermentation process conditions were obtained as the fermenting temperature 30℃, the initial pH 7.2, inoculating quantity 4% and fermenting time 38-4Oh.Under the optimal conditions,the maximum live cell concentration reached 3.98 x 109cfu/mL After fermentation,the microecological probiotics was prepared by emulsification and extrusion using 1% sodium alginate and 4% CaCI2.The live cell counting method was used to inspect the stability of the microecological probiotics. The stability tests showed that both of the survival rates of the microecological probiotics by emulsification and extrusion were much higher than unmicroencapsulation probiotics.Compared to the extrusion method,the emulsification preparation will be more suitable for large-scale industrial production.