Synergistic protease-lipase treatment for enhanced blood stain removal from textiles: Process optimization and efficacy evaluation

Abstract

This study investigates the synergistic effects of protease and lipase, produced from strains of Bacillus subtilis and Bacillus cereus, respectively, on blood stain removal from polyester and cotton fabrics. The effectiveness of enzyme - detergent combinations was evaluated using ΔE values as a quantitative measure of stain removal. Optimal culture conditions for enzyme production were determined using Response Surface Methodology (RSM) with Central Composite Design (CCD), identifying key variables such as temperature, pH, agitation, inoculum volume, and incubation time. Under optimized conditions, the enzymatic activity of protease and lipase reached 925.5 U/ml and 20.5 U/ml, respectively, representing a 2.4-fold and 3.1-fold increase compared to unoptimized conditions (376 U/ml for protease and 6.6 U/ml for lipase). Under optimal destaining conditions (pH 7.0, enzyme concentration of 1 mg/ml, and temperature of 60 °C), the combination of detergent, protease, and lipase achieved the highest ΔE values (58.42 ± 0.5 for polyester and 6.60 ± 0.5 for cotton fabric), signifying enhanced stain removal efficacy. Synergy between enzymes and detergents was highlighted, where detergent improved enzyme access to stain components, resulting in markedly improved cleaning efficiency compared to treatments with either enzyme or detergent alone. This study emphasizes the efficacy of enzyme-assisted formulations for sustainable textile cleaning applications.