Statistical Optimization of Culture Conditions by Response Surface Methodology for Synthesis of Α-Amylase with Indigenous Isolate of Bacillus KKC- 24

A soil bacterium capable of degrading starch on starch agar plates was isolated and identified as Bacillus isolates which designated as Bacillus KKC-17 – 24. Of the 8 isolates, the maximum alpha amylase producing Bacillus KKC-24 was seen by observation in Petridish of the clear zone of starch hydrolysis. A two stage method was used to optimise the conditions of cultivation for the production of α-amylase by this bacterium. The results were first analysed using the Plackett-Burman design on a variety of medium components. NaCl and CaCl2 have had a positive impact on the development of enzymes by different components tested while other variables have negative effects. However, due to a powerful curvature effect, the linear model was not sufficient to specify the optimal levels for these components. In the second step, to evaluate the optimum values, Box-Behnken response surface methodology was used. It was noted that the experimental data the matched correctly with a quadratic polynomial equation. The optimal concentrations for corn flour (g/L), peptone (g/L) and incubation periods (hrs) were found to be 12.83, 3.01 and 34.67 respectively, with an estimated value of alpha-amylase of 258.26 U/mL/ min. Practical alpha-amylase development hit 257.97 U/mL/min using this statistically optimised medium.