花生粕固态发酵产纳豆激酶的工艺优化

Optimization of fermentation conditions for nattokinase production in solid-state fermentation by Bacillus subtilis natto using peanut meal as substrate

探索纳豆菌固态发酵花生粕制备纳豆激酶的最佳工艺条件。以纳豆激酶活力为主要评价指标,在单因素实验基础上,通过正交实验优化花生粕固态发酵制备纳豆激酶的工艺条件。得出最佳发酵条件:发酵温度37℃,发酵时间24 h,接种量10%,料液比1∶0.4 g/m L。在此条件下测得发酵产物的纳豆激酶活力达到3162 U/m L,比单因素最高酶活提高了18%(2680 U/m L),可溶性氮含量为5.6 mg/m L,羟自由基清除率为74%,铁还原力的OD值为0.906。

The peanut meal was fermented by Bacillus natto to prepare nattokinase.The technological conditions were optimized by single factor and orthogonal experiments with a primary indicator of nattokinase.The results showed that the optimal conditions were as follows：fermentation temperature 37℃, inoculum size 10% ,the ratio of solid/liquid 1：0.4 g/mL,fermentation time 24 h.Under the optimized conditions,the activity of nattokinase reached 3162 U/mL, 18% higher than that obtained in one- factor- at- a- time experiments （ only 2680 U/mL）.And soluble nitrogen reached 5.6 mg/mL. Hydroxyl free radicals scavenging activity of fermentation broth was 74%, and the required absorbance for determining iron reduction capacities was 0.906.