Application of statistical design to the optimization of culture medium for prodigiosin production by Serratia marcescens SWML08

Abstract

Combination of Plackett-Burman design (PBD) and Box-Behnken design (BBD) were applied for optimization of different factors for prodigiosin production by Serratia marcescens SWML08. Among 11 factors, incubation temperature, and supplement of (NH 4) 2 PO 4 and trace salts into the culture medium were selected due to significant positive effect on prodigiosin yield. Box-Behnken design, a response surface methodology, was used for further optimization of these selected factors for better prodigiosin output. Data were analyzed step wise and a second order polynomial model was established to identify the relationship between the prodigiosin output and the selected factors. The media formulations were optimized having the factors such as incubation temperature 30 °C, (NH 4) 2 PO 4 6 g/L and trace salts 0.6 g/L. The maximum experimental response for prodigiosin production was 1397.96 mg/L whereas the predicted value was 1394.26 mg/L. The high correlation between the predicted and observed values indicated the validity of the statistical design.