一株饲用益生蜡样芽孢杆菌的液体发酵研究

目的]为探明蜡样芽孢杆菌的液体发酵规律。方法]以玉米粉+豆粕粉+硫酸锰+硫酸镁+磷酸二氢钠+磷酸氢二钠+植物油为发酵培养基,在(30±1)℃、初始pH值7.2、通气量1.5 m3/h、罐压0.04 Mpa、发酵周期54 h条件下,对蜡样芽孢杆菌MYSLY-02进行发酵培养。测定发酵过程中菌体数量及芽孢形成率等的变化。结果]培养0~6 h时,芽孢杆菌菌体小、数量少,糖度基本不变;培养6~36 h时,菌体数量急剧增多,菌体增大增长,并开始形成芽孢,糖大量消耗;培养36~54 h时,菌体数量基本稳定,菌体基本形成芽孢,糖消耗减慢;培养54 h后,菌体数量减少,部分芽孢开始脱落。反应结束时,细菌浓度达到9.5×109CFU/ml,芽孢形成率达到92%。结论]确定了蜡样芽孢杆菌液体发酵的最佳条件。

Study on Liquid Fermentation of One Strain Feed Probiotics Bacillus cereus

Objective] The aim was to study the liquid fermentation rules of Bacillus cereus.Method] With corn meal +bean cake powder +manganese sulfate +magnesium sulfate +sodium dihydrogen phosphate +disodium hydrogen phosphate +vegetable oil as the fermentation medium,under the condition of(30±1)℃,initial ph value of 7.2,ventilation volume of 1.5 m3/h,jar-pressure of 0.04 Mpa, fermentation period of 54 h,the fermentation culture of B.cereus MYSLY-02 was done.The change of thallus number and spore forming rate in fermentation process were determined.Result] When cultured for 0-6 h,the thallus of B.cereus was small,and its number was few,and the sugar degree was almost invariant.When cultured for 6-36 h,the number of thallus increased dramatically,and the thallus became big and long,and the thallus began to form spore and the sugar was consumed a lot.When cultured for 36-54 h,the number of thallus was stable,and the thallus basically formed spore and sugar consumption was slower.After culture for 54 h,the number of thallus decreased,and some spore began to fall off.When the reaction finished,the concn.of bacteria was 9.5×109 CFU/ml and the forming rate of spore reached 92%.Conclusion] The optimum condition for liquid fermentation of B.cereus was determined.