Optimization of medium composition for alkaline protease production by Marinobacter sp. GA CAS9 using response surface methodology – A statistical approach

In the present study, the alkaline protease producing Marinobacter sp. GA CAS9 was isolated from the marine ascidian Polyclinum glabrum and identified by 16S rRNA analysis. Medium components and culture conditions for alkaline protease production were optimized using statistical optimization. Plackett–Burman design was employed to find out the optimal medium constituents and culture conditions to enhance protease production. Central composite design revealed that four independent variables, such as NaCl (60.53 g/l), beef extract (14.73 g/l), CuSO4 (4.73 g/l) and pH (10.7) significantly influenced the protease production. Protease production obtained experimentally coincident with the predicted value and the model was proven to be adequate. The enhancement of protease from 298.34 U/ml to 982.68 U/ml was achieved with the optimization procedure.