采用响应面方法对黑曲霉(Aspergillus niger357)产酸性蛋白酶的发酵条件进行了优化。首先通过全因子实验分析了温度、pH值、接种量、装液量对产酶的影响,确定主要影响因子为温度、装液量,前者为正影响,后者为负影响。用最陡爬坡实验逼近最大响应区域,利用中心组合设计及响应面分析确定主要影响因子的最佳水平。在优化的发酵条件下发酵3d,酶活达到1543、01U/mL。
Response surface methodology was employed to optimize the fermentation conditions of Aspergillus niger for producing acid protease. In the first optimization step, a full factorial design was used to investigate the effect of temperature, initial pH, inoculum and medium volume on the production of acid protease from A. niger. The results showed that temperature and medium volume had significant effect on protease production, the former had positive effect, while the latter had negative effect. The steepest ascent path was used to approach the optimal region of the protease production. The optimal level of temperature and medium volume was determined by a central composite design and response surface analysis. The maximum activity of acid protease was 1543,01 U/ml under the optimized conditions after 3 d.