Production and Optimization of Alkaline Protease by Bacillus spp. Isolated from Tannery Industry and Potential Biotechnological Application of the Enzyme

: Four Bacillus spp. strains isolated from the effluents of tannery industries (Dhaka, Bangladesh) showing proteolytic activity were studied to determine their alkaline protease enzyme production capability. They were also optimized with respect to initial medium pH and temperature. Their range of enzyme activity were between 47.84 and 179.13 U/ml, initially. The optimum initial media pH was 10.0 for B. subtilis B20, 9.0 for both B. subtilis PB18 and Bacillus sp. BVC38 and 7.0 for B. amyloliqefaciens Egy25. Optimum temperatures were determined as 60° C for both B. subtilis B20 and PB18 and 40 °C for the other two organisms. After optimization, alkaline protease production capability of B. subtilis B20 and PB18 was increased to 301.80 and 255.34 U/ml, respectively. The crude enzyme of B. subtilis B20 with better wash performance analysis (visually) and an optimum pH 10.0 and 60° C temperature can be considered as a potential candidate for biotechnological application in detergent industry. The crude alkaline proteases produced by the four organisms were also tested for their dehairing potentiality of raw hides and enzymes from B. subtilis B20 and PB18 showed better results of dehairing like lime-sulphide chemical treatment, which can be considered as environment friendly alternative to the hazardous chemical treatment in tannery industries.