Medium composition and culture conditions for the acid protease production by Aspergillus niger I1 were optimized by response surface methodology (RSM). A significant influence of temperature, KH2PO4, and initial pH on the protease production was evaluated by Plackett-Burman design (PBD). These factors were further optimized using Box-Behnken design and RSM. Under the proposed optimized conditions, the experimental protease production (183.13 U mL−1) closely matched the yield predicted by the statistical model (172.57 U mL−1) with R2 = 0.914. Compared with the initial M1 medium on which protease production was 43.13 U mL−1, a successful and significant improvement by 4.25 folds was achieved in the optimized medium containing (g/L): hulled grain of wheat (HGW) 5.0; KH2PO4 1.0; NaCl 0.3; MgSO4(7H2O) 0.5; CaCl2 (7H2O) 0.4; ZnSO4 0.1; Na2HPO4 1.6; shrimp peptone (SP) 1.0. The pH was adjusted at 5 and the temperature at 30°C. More interestingly, the optimization was accomplished using two cheap and local fermentation substrates, HGW and SP, which may result in a significant reduction in the cost of medium constituents.
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机译:通过响应面法(RSM)优化了黑曲霉I1产生酸性蛋白酶的培养基组成和培养条件。通过Plackett-Burman设计(PBD)评估了温度,KH2PO4和初始pH对蛋白酶产生的显着影响。使用Box-Behnken设计和RSM进一步优化了这些因素。在建议的优化条件下,实验蛋白酶的产量(183.13 U mL-1)与统计模型(172.57 U mL-1)预测的收率非常匹配,R2 = 0.914。与最初的M1培养基的蛋白酶产量为43.13 U mL-1相比,在含有(g / L)的优化培养基中,成功的显着提高了4.25倍:小麦脱壳谷物(HGW)5.0; KH2PO4 1.0;氯化钠0.3; MgSO4(7H2O)0.5; CaCl2(7H2O)0.4;硫酸锌0.1; Na2HPO4 1.6;虾蛋白ept(SP)1.0。将pH调节至5,并将温度调节至30℃。更有趣的是,使用两种廉价的本地发酵底物HGW和SP进行了优化,这可能导致培养基成分的成本大大降低。
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