Statistical optimization of alkaline protease production from brackish environment Bacillus sp. SKK11 by SSF using horse gram husk

Protease production by Bacillus sp. SKK11 isolated from brackish environment was studied by solid-state fermentation with horse gram husk. Response surface methodology-based Box-Behnken design (BBD) was used to optimize the variables such as pH, maltose, and MgSO₄. The BBD design analysis showed a reasonable adjustment of the quadratic model with the experimental data. Statistics-based contour and three-dimensional (3-D) plots were generated to evaluate the changes in the response surface and to understand the relationship between the enzyme yield and the culture conditions. The maximum yield of the enzyme was observed at pH 9.0.