一株产酸蜡样芽孢菌的筛选鉴定及发酵条件优化

Screening and performance testing of an acid producing Bacillus cereusstrain

从牛粪中分离得到一株产酸芽孢菌GF1,经鉴定为蜡样芽孢杆菌,该菌株发酵最低pH值可达到4.25,发酵最终芽孢率可达到90%以上,对该菌株液体发酵培养发现GF1具有良好的生长性能,通过优化培养条件和培养基中的C源、N源,最终确定GF1发酵条件为:发酵液初始pH值7.5,摇床转速220 r/min,培养温度35℃,培养时间48h,配方为:酵母膏0.5%,蛋白胨0.6%,葡萄糖1.0%,K2HPO40.5%,MgSO40.02%,MnSO40.08%。

GF1 was isolated from cow dung and identified as Bacillus cereus. The liquid fermentation studies of GF1 showed that it had a good growth performance. The parameters of cultivation and the density of carbon source and nitrogen source of the culture were optimized. The results showed that the optimal cultivation conditions for GF1 were the medium original pH 7.5, culture temperature 35℃, rotation speed 220 r/min, cultivation time 48 h. The medium was comprised of yeast extract 0. 5% , peptone 0. 6% , glucose 1.0% , K2HPO4 0.5% , MgS04 0.02% , MnS040.08%.