production and optimization of amylase by bacillus polymyxa ncim no. 2539 utilizing agro-industrial byprodut (orange peel)

background and objective: in the present study, bacillus polymyxa ncim no. 2539 was selected to utilize agro-industrial byproduct (orange peel) for amylase production under submerged fermentation conditions. material and methods: different agro-industrial byproducts like cane molasses, wheat bran, rice bran and orange peel were screened for maximum amylase production. amylase activitiy of bacillus polymyxa was studied using starch-agar plate method. minitab software version 17 and central composite design were applied to evaluate effect of supplementation of substrate with different sulphur containing amino acids (cysteine, methionine and cystine) and vitamin thiamine on enzyme activity. further optimization of the parameters viz. amount of substrate, concentration of amino acid and vitamin for maximum amylase production was studied by central composite rotatable design. results and conclusion: among 4 different agro-industrial substrates applied, orange peel showed maximum enzyme production (activity: 492.31 iu g-1 sample). supplementation of the production media with cysteine showed maximum amylase production (515.38 iu g-1 sample) among all three amino acids and control. supplementation with thiamine also showed more amylase production (469.23 iu g-1 sample) as compared to control (415.38 iu g-1). cysteine and thiamine proved to increase amylase production significantly. maximum amylase production was obtained at 7.7 g orange peel, 37.29 mg cysteine and 34.23 mg per 10 ml thiamine. conflict of interest: the authors declare no conflict of interest.