Optimization and production of alpha-amylase using Bacillus subtilis from apple peel: Comparison with alternate feedstock

Abstract

Degradable waste generated from food processing industries has immense potential for producing valuable products. Apples constitute among the most widely consumed fruits in the food processing industry, but their peels remain unutilized. We explored the possibility of using apple peel as feedstock for production of alpha-amylase- a commercially important enzyme with role in food industry and bio-ethanol production that is critical to support nutrition and energy security. The utilization of locally sourced apple peel as feedstock, optimization of the conditions for the production of alpha-amylase through solid-state fermentation and comparison with potato peel-another widely available feedstock option is done. The Bacillus subtilis BS1934 strain was identified as a promising strain that could produce alpha-amylase efficiently at 50 0C. The obtained values i.e., 17468 and 5229 U/L of alpha-amylase from apple and potato peel, respectively through solid state fermentation in eight days were considered as optimum. The enzyme titres were 3-fold higher with apple peel as compared to potato peel in the medium, indicating superior quality of apple peel feedstock as compared to potato for amylase production. The production of amylase using agro-industrial residues, as apple peel may emerge as a cost-effective alternative to amylase from microbial sources for industrial purpose.