花生粕固态发酵产纳豆激酶的工艺优化

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。 

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

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 / m L,fermentation time 24 h.Under the optimized conditions,the activity of nattokinase reached3162 U / m L,18% higher than that obtained in one-factor-at-a-time experiments( only 2680 U / m L). And soluble nitrogen reached 5.6 mg / m L. Hydroxyl free radicals scavenging activity of fermentation broth was 74%,and the required absorbance for determining iron reduction capacities was 0.906.