Optimization of Culture Medium for Anti-fungus Compound Produced by Streptomyces 702 by Means of Response Surface Method Under Unsterilized Condition

The response surface method was used to optimize the culture medium for anti-fungus compound produced by Streptomyces 702 under unsterilized condition.In the first optimization step cornstarch and peptone were screened out,which were the critical factors affecting anti-fungus compound produced by Streptomyces 702 using Fractional Factorial Design.Then the steepst ascent path was used to approach the optimal region of the medium composition.In the third step the optimal concentration of cornstarch and peptone were determined by a central composite design and response surface analysis.The optimum concentration of cornstarch and peptone were 16.83g/L,8.64g/L,under the optimum medium the anti-fungus compound production was increased from 789.41μg/mL to 1214.52μg/mL by 53.85%.