Media Optimization for Amylase Production through OFAT Using Onion Peel as Substrate

¹ Amity Institute of Food Technology, Amity University, Noida, India
² Amity Institute of Bio-Technology, Amity University, Noida, India
³ Shriram Applied Radiation Centre, Shriram Institute for Industrial Research, Delhi, India

^* Corresponding author: anilazahid05@gmail.com, rdkhedkar@amity.edu

Abstract

Amylase is a vital enzyme with extensive industrial applications, including in food processing, textiles, and biofuels. This study explores a novel and sustainable approach to amylase production using Bacillus subtilis and onion peel, an agro-industrial waste product, as a substrate by using OFAT(One-Factor-At-a-Time) technique. Onion peel, rich in carbohydrates and nutrients, was utilized to enhance enzymatic activity while reducing production costs and promoting waste valorization. A systematic optimization of media components, including substrate concentration, nitrogen source, pH, and temperature, was performed to maximize bacterial growth, enzyme activity, and protein production. The optimized conditions—15 g/L substrate concentration, peptone (2 g/L) as the nitrogen source, neutral pH (pH 7), and a temperature of 37°C yielded the highest bacterial growth (OD 1.00), enzyme activity (0.38 μmol/min), and protein concentration (0.60 mg/ml). Purification of the enzyme using 40% ammonium sulfate precipitation achieved a twofold increase in specific activity (40 U/mg) with an 80% yield, demonstrating the effectiveness of the purification process. This research highlights the potential of onion peel as a sustainable and cost-effective substrate for microbial enzyme production. The findings not only contribute to advancing enzyme production processes but also align with global efforts to adopt eco-friendly and sustainable industrial practices. The study offers a scalable framework for enhancing amylase production and paves the way for its application in diverse industrial sectors.