Production and optimization of alpha amylases using banana waste by Bacillus licheniformis DS3 under solid state fermentation

Abstract

Amylases producing 10 bacterial strains were isolated from banana rhizosphere collected from Guntur, Andhra Pradesh, India, thereafter screened for amylase activity. Among them Bacillus licheniformis DS3 strain showed maximum zone of clearance in starch hydrolysis test was selected for this study. Identification of Bacillus licheniformis DS3 was confirmed by 16S rRNA sequencing analysis. In this context, different agro wastes like Banana peel, Potato peel, Orange peel, Rice husk, Maize straw and Sugarcane bagasse were tested for alpha amylase production. Among them banana peel containing the medium was found to be best for maximum amylase production. The various process parameters were optimized for Alpha amylases production including incubation period, temperature, pH concentrations and addition of different carbon and nitrogen sources. The strain B. licheniformis DS3 produced maximum amount of amylase after 48 h of incubation, 40⁰ C temperatures at pH 7.0 with banana peel as the substrate. Considerable enzyme production (1140 U/ml) was observed by using banana peel as substrate. Addition of carbon and nitrogen sources in the banana peel medium greatly influenced the amylase the production. Maximum production was observed in starch (1430 U/ml) and yeast extract (1330 U/ml) used as carbon and nitrogen sources.