高产α-葡萄糖苷酶黑曲霉的微波选育及发酵条件优化

采用微波诱变技术对黑曲霉J2进行选育,得到1株α-葡萄糖苷酶活力较高的突变菌株ANY-4,酶活力达到305 U/mL,比出发菌株提高了38.6%,且稳定性良好。通过单因素和正交试验得到最适培养条件为:玉米淀粉80 g/L、玉米浆干粉40 g/L、初始pH 4.5、装液量50 mL/500 mL、接种量3%、培养温度36℃、摇床转速240 r/min、培养时间40 h。在最优培养条件下进行发酵,α-葡萄糖苷酶活力达到427 U/mL,比优化前提高了40%。

Microwave Breeding of Aspergillus niger with High α-Glucosidase Activity and Optimization of Its Fermentation Conditions

α-Glucosidase is the key enzyme involved in the production of isomaltoligosaccharides which are widely applied
in the food, medicine, health care and feed industries. A mutant Aspergillus strain named ANY-4, with high α-glucosidase
activity and good genetic stability, was obtained from Aspergillus niger J2 via microwave-induced mutation. Its enzymatic
activity was 305 U/mL, which was 38.6 % higher than that of Aspergillus niger J2. To produce α-glucosidase with a high
yield, single factor experiments and orthogonal array design methods were performed to determine the optimal fermentation
conditions as follows: corn starch 80 g/L, corn steep liquor powder 40 g/L, initial pH 4.5, fermentation medium volume
50 mL in 500 mL flasks, inoculum quantity 3% (V/V), 36 ℃, 240 r/min and fermentation for 40 h. Under these conditions,
the α-glucosidase activity was 427 U/mL, which was increased by 40% as compared to that obtained before optimization.