Statistical optimization of medium components for the production of lipase by Serratia marcescens SB08

Abstract

The optimization of the fermentation medium and conditions for maximum lipase production was carried out using a new strain, Serratia marcescens SB08. The results of factorial design showed that CaCl 2, incubation time, pH and yeast extract were the key factors affecting lipase production. The optimal cultural conditions for lipase production obtained with central composite design was pH 7.0, incubation time 51 h, yeast extract 3.0 g/L and CaCl 2 0.13 g/L. The model was also validated by repeating the experiments under the optimized conditions, which resulted in the lipase production of 243.91 U/mL (Predicted response 251.83 U/mL), thus proving the validity of the model. Lipase enzyme was purified and the molecular weight was found to be 52 KDa. In this work the use of a central composite design by determining the conditions leading to the high yield of enzyme production has been demonstrated. Thus, smaller and less time consuming experimental designs could generally suffice for the optimization of many fermentation processes.