Optimisation of the conditions for protease synthesis from Bacillus subtilis Bs04 and characterisation of the enzyme

Abstract

Proteases are the most commonly used enzyme in many fields such as medicine, industry, agriculture, etc. In this study, we optimized fermentative conditions from Bacillus subtilis Bs04 to obtain the highest concentration and activity of the secreted protease. The effects of main medium ingredient, physicochemical parameter and characteristics of the protease were investigated. The result showed the optimal conditions for protease production from Bs04: the best organic carbon and nitrogen source are glucose-anhydrous and yeast extract with concentration of 2% and 2.5%, respectively; medium pH 7.5; enzyme obtained after 36 hours of fermentation. Maximum activity was obtained by ammonium sulfate precipitation method with the 70% saturation. The results of SDS-PAGE showed two bands with a molecular weight of 24 kDa and 38 kDa, respectively.