低温β-半乳糖苷酶产生菌14-1摇瓶发酵研究

Studies on the conditions of cold-adapted β-galactosidase flask fermentation by strain 14-1

对低温菌株14-1进行了摇瓶条件下的产低温β-半乳糖苷酶的研究。首先考察了菌的生长温度特性,产酶最佳温度及产酶高峰期,然后研究了培养基中乳糖质量分数,培养基初始pH值,溶氧水平,接种量,以及Tween80对酶活的影响。确定了摇瓶最佳的发酵工艺条件:乳糖质量分数为2.5%,接种量3%(质量分数),培养基初始pH值为6.5,表面活性剂Tween80为1.0%,装液量为在500 mL三角瓶装液体培养基100 mL。20℃培养48 h,14-1菌产低温β-半乳糖苷酶活性4.51 U/mL。

Shake-flask culture conditions of cold-adapted β-Galactosidase were studied with psychrotrophic strain14-1. The paper firstly in- vestigated the growth temperature characteristic, the optimum temperature and time for producing enzyme of 14-1.Then the effects of lactose concentration in fermentation medium, initial pH, dissolved oxygen concentration, the amount of seed, and Tween80 on β-Galactosidase activities were discussed. It was suggested that the better fermentation condition on laboratory scale was as following： lactose concentration 2.5%, initial pH 6.5, seed 3%, Tween80 1.0%, 500 mL flask contained 100mL medium. The maximum ]3-Galactosidase activity, about 4.51 U/mL, was obtained at 20 ℃ when cultured for 48 h.