Statistical optimization of medium components for avilamycin production by Streptomyces viridochromogenes Tu57-1 using response surface methodology

A fermentation medium for avilamycin production by Streptomyces viridochromogenes Tu57-1 has been optimized. Important components and their concentrations were investigated using fractional factorial design and Box-Behnken Design. The results showed that soybean flour, soluble starch, MgSO4 center dot 7H(2)O and CaCl2 center dot 2H(2)O are important for avilamycin production. A polynomial model related to medium components and avilamycin yield had been established. A high coefficient of determination (R-2 = 0.92) was obtained that indicated good agreement between the experimental and predicted values of avilamycin yield. Student's T-test of each coefficient showed that all the linear and quadratic terms had significant effect (P > vertical bar T vertical bar < 0.05) on avilamycin yield. The significance of tested components was related to MgSO4 center dot 7H(2)O (0.37 g/L), CaCl2 center dot 2H(2)O (0.39 g/L), soybean flour (21.97 g/L) and soluble starch (37.22 g/L). The yield of avilamycin reached 88.33 +/- 0.94 mg/L (p < 0.05) that was 2.8-fold the initial yield.