Bacillussp.HA-1产环糊精葡萄糖基转移酶发酵工艺研究

在10 L 发酵罐中,研究了环糊精葡萄糖基转移酶产生菌 Bacillus sp．HA-1的发酵规律,结果表明,在菌体对数增长期,发酵液溶氧处于较低状态,发酵液 pH 在对数增长前期持续下降,中期后回升,菌体产酶呈增长趋势；当菌体增长进入稳定期,发酵液溶氧迅速回升至初始状态,pH 也回升至起始值,菌体产酶接近峰值。根据发酵规律优化发酵工艺,通过有效增加菌体对数增长期发酵液溶氧,使菌株产酶到达高峰的时间缩短了 50%以上。应用该菌株在5 m~3生产罐中发酵,24 h 产酶水平达到6 800 IU/mL。

Studies on Zymotechnique of Cyclodextrin Glucanotransferase by Bacillus sp. HA-1

Fermentation of Bacillus HA-1 strain to produce cyclodextrin glucanotransferase (CGTASE) was carried out in a 10 L tank in this study.It is seen that during the exponential phase the dissolution oxygen of medi- um was very low.It is also seen that the pH of medium dropped at the prophase and increased after the metaphase while the CGTase concentration increased continually.During the stationary phase,the dissolution oxygen,pH of medium returned to their original level,but the maximal yield of CGTase yield was obtained at the time.The fer- mentation conditions were optimized.By increasing the dissolution oxygen of medium at the exponential phase,the time to reach enzyme activity peak was shortened by 50%.The strain could produce as much as 6 800 IU/mL of CGTase when cultivated for 24 hours in a 5m~3 tanks.