Valorization of Fermentation Waste: Eco-Friendly Synthesis of Antimicrobial Bacterial Cellulose-Silver Nanocomposites Using Post-Fermentation Solution as a Reducing Agent

Abstract

This study presents a green approach for synthesizing antimicrobial bacterial cellulose-silver nanoparticles (BC/AgNPs) utilizing the residual sugar-containing post-fermentation solution (4.05 g/L) as a reducing agent. The treated post-fermentation solution effectively reduced silver ions into uniformly distributed crystalline AgNPs of approximately 100 nm size within the BC matrix, as confirmed by XRD, FTIR, and SEM analyses. FTIR revealed interactions between AgNPs and BC hydroxyl groups. The synthesized BC/AgNPs exhibited potent antimicrobial activity against Escherichia coli, with the 1:1 AgNO₃:BC ratio demonstrating superior efficacy. This valorization of the waste stream into a functional reducing agent aligns with sustainable principles, minimizing waste while enabling efficient resource utilization to produce antimicrobial nanocomposites with potential applications in biomedicine, food packaging, and environmental remediation.