Optimization and partial characterization of amylase produce by Bacillus cereus KR9 using Response surface methodology

Amylases are considered to be the most prominent enzyme as they are used in brewing, detergent and textile industries. Since characterizing the enzyme activity is prerequisite for its relevant application, this study aimed to optimize the enzyme activity for different parameters. Bacillus cereus KR9 using submerged fermentation with wheat bran as substrate and optimum inoculum percentage of 3% (v/v) exhibit amylase activity of 29.19U/ml after 48 h of incubation. The partially purified enzyme of Bacillus cereus KR9 showed was highly stable at pH 8.0 with residual activity of 92%. Response surface methodology (RSM), Box- Behnken design was employed to optimize the activity α-amylase of strain KR9. The combinational effects of the factors like substrate concentration, temperature and metal ion concentration were found to have significant effects on α-amylase activity. The maximum amylase activity was 307.67 U/ml under the optimized experimental conditions of substrate concentration of 1 % (w/v), temperature of 47 °C and with 5 mM CaCl2 mM respectively. Partially Purified enzyme was observed in SDS- PAGE and zymogram analysis with a molecular weight of approximately 54 kDa. The strain showed significant compatibility with commercial laundry detergents and good wash performance thus providing its suitability for detergent formulation. It efficiently decolorized the tested dyes saffranin (57.7%) and crystal violet. (64.35%). The results encourage the use of Box - Behnken response surface methodology for optimizing the α-amylase activity of and form exceptional basis for the further large-scale textile applications and biotechnological utilization.