A central composite design for the optimizing lipase and protease production from Bacillus subtilis PTCC 1720

In the present study, the producing condition of lipase and protease from Bacillus subtilis PTCC 1720 was optimized by response surface methodology (RSM). A central composite design (CCD) was used to evaluate the interactive effect of the enzyme production conditions on the lipase activity (LA), protease activity (PA) and biomass of B. subtilis PTCC 1720. Independent variables including temperature, sucrose, peptone, and corn oil concentration were studied. According to the results, the optimal enzyme production condition was achieved with temperature of 43.4 °C, sucrose of 20 g/L, peptone of 20 g/L, and corn oil of 4 mL/L. In this conditions the LA, PA, and biomass were predicted 3.16 U/mL, 1744.6 U/mL, and 3.03 g/L, respectively. The experimental and predicted values of the LA, PA, and biomass show a good agreement with one another, with a high degree of accuracy of the models.