响应面法优化米曲霉液体发酵生产中性蛋白酶工艺

摘要

To improve the neutral protease-producing ability of Aspergillus oryzae with liquid-state fermentation, the carbon source, nitrogen source and inorganic salts were screened by single factor tests and Plackett-Burman(PB)experiments.The optimum formulas were optimized by response surface methodology to improve the activity of neutral protease in the production of A.oryzae fermentation.The results showed that the optimum carbon source, nitrogen source and inorganic salts were corn flour, beef extract and calcium chloride, respectively.The optimum fermentation conditions were corn flour 17 g/L, beef extract 10 g/L, calcium chloride 0.04 g/L, inoculum 5％, liquid volume 60 ml/250 ml, fermentation temperature 30 ℃ and time 84 h.Under the conditions, the activity of neutral protease increased from 21.4 U/ml to 1 10.5 U/ml.%为提高米曲霉(Aspergillus oryzae)液体发酵生产中性蛋白酶的能力,采用单因素试验、Plackett-Burman (PB)试验筛选碳源、氮源和无机盐,并通过响应面法优化其最佳配比,提高米曲霉液体发酵生产中性蛋白酶的活性.结果表明,米曲霉液体发酵生产中性蛋白酶的最佳碳源、氮源和无机盐分别为玉米粉、牛肉膏和氯化钙,发酵的最优条件为玉米粉添加量17 g/L,牛肉膏添加量10g/L,氯化钙添加量0.04 g/L,接种量5％,装液量60 mL/250 mL,于30℃条件下发酵84 h.在此优化条件下,产生的中性蛋白酶活性从最初的21.4 U/mL提高至110.5 U/mL.