黑曲霉a-鼠李糖苷酶高产菌株的选育

Screening of α-Rhamnosidase High-yield Strain from Aspergillus niger

摘要:

本文首次报道利用Davis方法制备的透明圈法筛选α-鼠李糖苷酶高产菌株。用甲基磺酸乙酯对出芽8 h的黑曲霉孢子进行诱变处理, 用透明圈法初筛出的菌株中, 产量提高40%以上的突变菌株占11%; 用摇瓶培养对初筛出的菌株进行两轮复筛α-鼠李糖苷酶高产突变株T-226, 摇瓶培养α-鼠李糖苷酶活达373.4 U/mL, 比出发菌株提高了22.7%。对该高产突变株进行5 L罐发酵实验, 发酵84 h测得α-鼠李糖苷酶活为631.9 U/mL。用新建立的方法选育高产α-鼠李糖苷酶的高产菌株, 不仅具有较高的筛选效率, 还具有良好的准确性。

Abstract:

In this study, plate transparent circle by Davis method was introduce firstly screening α-Rhamnosidase high-yield strain. The spore-sprouted Aspergillus niger 8-hour were mutagenized by ethyl methane sulphonate and pre-screened via transparent circle. 11% mutants yield 40% higher of α-rhamnosidase than the original strain. A high-yield strain, T-226 with the highest α-rhamnosidase activity of 373.4 U/mL was finally selected from these potential high-yield mutants after rescreened by shake flask fermentation twice. When the T-226 strain was fermented in 5 L bioreactor, the enzyme activity could reach to 631.9 U/mL after 84 h. Thus, the established screening method is highly efficient to isolate α-rhamnosidase high-yield mutant of A. niger.