Medium Optimization for Antifungal Active Substance Production from Streptomyces Lydicus Using Response Surface Methodology

摘要

Response surface methodology was used to optimize the medium for antifungal active substance pro-duction from Streptomyces lydicus E12 in flask cultivation. Initially, the component factors, which influence antifungal substance production, were studied by varying one factor at a time. Starch, soybean cake powder, K2HPO4?3H2O and MgSO4?7H2O were found to have a significant effect on the production of antifungal substances by the traditional design. Then, a Box–Behnken design was applied for fur-ther optimization. A quadratic model was found to fit antifungal active substance production. The analysis revealed that the optimum values of the tested variable were starch 84.96 g/L, soybean cake powder 4.13 g/L, glucose 5 g/L, MgSO4?7H2O 1.23 g/L, K2HPO4?3H2O 2.14 g/L and NaCl 0.5 g/L. The test result of 67.44%antifungal inhibition agreed with the prediction and increased by 14.28%in comparison with the basal medium.