Cost-Effective Production, Optimization, and Characterization of Alternaria citri Amylase as a Detergent Additive

Optimized amylase production from Alternaria citri using low-cost waste materials was achieved, and the resulting enzyme was subsequently purified and biochemically characterized. Fermentation parameters were optimized for maximum amylase production at pH 6.0, 30°C, and 72 h incubation period, using potato peel powder as the substrate at 1%. Crude enzyme was purified by ammonium sulfate precipitation, dialysis, and gel filtration chromatography. Biochemical characterization revealed that the enzyme showed maximum catalytic activity at 50°C and pH 6.0. Kinetic analysis indicated a low K_m of 0.34 ± 0.008 mg/mL and a high V_max value of 0.52 ± 0.037 mg/mL/min, indicating strong substrate affinity and an efficient reaction rate. The enzyme showed good residual activity toward several additives. Amylase showed 85%-100% and 100%-140% activity in the presence of detergents at 40°C and 50°C, respectively, indicating excellent stability and compatibility with commercial detergents. Wash performance analysis further confirmed amylase's suitability as an additive for commercial detergents. The findings establish A. citri-derived amylase as a robust, thermostable, and industrially relevant biocatalyst utilizing waste materials, with significant potential for application in detergent formulations and other biotechnological processes.