研究了两段培养中基质浓度、配比及天然氮源添加方式对重组酵母发酵生产α-淀粉酶的影响。结果表明，重组酵母发酵适宜的初糖浓度为7g·L-1，葡萄糖和基础氮配比为7:4，生长期补料碳氮比为5:1，且产酶期供给天然氮源以少量多次脉冲补加酵母膏为宜。于2L发酵罐中培养，证明脉冲补加酵母膏、流动添加基本营养物的补料分批培养方式是有效的，指数流加基本营养物较之恒流量流加更能提高菌体浓度和a-淀粉酶表达水平。培养60小时细胞量达24.5g·L-1，酶活力达97.3U·mL-1%The effects of initial sugar concentration、ratio of glucose andyeast nitrogen base (without amino acid) and the different natural nitrogen feeding strategy in the expression stage on the production of α-amylase by recombinant yeast in shaking flask two-stage culture were investigated. The results showed that the proper initial sugar concentration was 7g·L-1, ratio of glucose and yeast nitrogen base was 7:4, ratio of carbon and nitrogen of the feeding nutrition was 5:1 respectively. The suitable feeding strategy of natural nitrogen source in the expression stage is " pulse feeding in a small amount of it". By the cultivation in 2L fermentor, it was confirmed that feeding basic nutrition and pulse feeding yeast extract were effective feeding strategy .The pulse feeding based on exponential feeding principle has more advantages than constant feeding in both enhancing cell mass and a-amylase productivity. The maximum cell density and a-amylase activity reached 24.5g·L-1 at 27h and 97.3U·mL-1 at 57h, respectively.
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