Improved production of acrylamidase from Bacillus tequilensis through response surface methodology

Amidase, a biocatalyst for the biotransformation of nitrile amides into various commercial carboxylic acids, is used in the pharmaceutical industry, in the chemical industry, and in the treatment of wastewater. It has been observed that the synthesis of amidase enzyme relies on several media compositions. The present study focused on increased synthesis of intracellular amidase from a novel thermotolerant bacteria Bacillus tequilensis by response surface methodology (RSM). RSM with a central composite design (CCD) was used to examine the effect of independent variables (starch, peptone, and mineral base) on response variables. From the RSM model, it was confirmed that the experimental results were appropriate in the statistical model of quadratic polynomial with R² values greater than 0.900 for the two responses. An optimized condition consisting of 5.413 g/l starch, 1.113 g/l peptone, and 150 ml/l mineral base respectively was reported for amidase activity. The experimental values of the enzyme activity and biomass production were 8.453 I.U. and 3.213 g/l at optimized conditions. Using the statistical approach, 1.4 times increment on acrylamidase production was observed over the unoptimized experimental values.