Ethyl Methane Sulfonate Chemical Mutagenesis of Ba- cillus subtilis for Enhanced Production of Protease

Abstract

The enzymes have acquired a great importance in the industries. They are important industrial catalyst used in food, detergent and leather tanning industries. Chemical mutagenesis of Bacillus subtilis was carried out using ethyl methane sulfonate. Mutants of Bacillus subtilis was isolated and evaluated for production of protease to select the best producer mutant strain. Protease production by the best selected mutant was optimized by varying temperature, pH, inoculum size and incubation time in Response Surface Method under Central Composite Design. The mathematical response model is reliable with an R2 value of 0.9833. The adjusted R2 value was 0.9677 suggesting a significant model by determining the close relationship to the actual R2 value. Predicted R2 value shown in this model was 0.9355. The “Pred R-Squared” of 0.9355 is close as to the “Adj R-Squared” of 0.9677 as expected. The ratio of 31.34 attained in this model represents an adequate signal. The calculated C.V was 2.49 which indicates the good level of model precision and reliability. The maximum enzyme activity was 256.004 (IU/mL) at optimum conditions pH 10, Temperature 35o C, Inoculum size 4mL and fermentation time 120hr. These characteristics render its potential use in detergent industries for detergent formulation.