Optimization of physicochemical parameters for maximum amylase production by indigenously isolated Bacillus cereus AS2 strain

Abstract

Amylases are enzymes that catalyze the hydrolysis of starch into highly valuable products of economic significance. Amylases are used extensively in various industrial sectors. Microbial sources particularly Bacillus species are well known for the cost effective commercial production of amylase enzyme. Present study focuses on the enhancement of amylase enzyme production from an indigenously isolated Bacillus cereus AS2 strain via one variable at a time (OVAT) optimization of different physical and chemical factors. Purposely, eight parameters possibly affecting the amylase production including temperature, pH, incubation time, inoculum size, substrate concentration, metal ions, carbon and nitrogen sources were investigated. According to the results, amylase production was significantly boosted at maximum when the Bacillus cereus AS2 was grown at 45°C on pH 7.0 for 72 hours in the medium supplemented with 4% starch and 0.5% glycine. Among the different metal ions tested, CaCl2 (0.05%) was found significant to accelerate extracellular amylase production