Fungal-Derived Chitosan from In Vitro Mushroom Cultures as an Antimicrobial Matrix for Silver Nanoparticles in Advanced Bioactive Materials

This study investigates chitosan extracted from in vitro cultures of Hericium erinaceus and Pleurotus ostreatus mushrooms as a novel antimicrobial matrix. The physicochemical properties including specific surface area, pore volume, and molecular structure were characterized by BET, SEM, and FTIR-ATR analyses. Chitosan from P. ostreatus exhibited a higher specific surface area (0.39 m2/g) compared to H. erinaceus (0.73 m2/g) and commercial chitosan (1.16 m2/g), correlating with enhanced antimicrobial activity against Gram-negative and Gram-positive bacterial strains. Antibacterial efficacy was quantitatively evaluated by inhibition zone diameters, with P. ostreatus chitosan combined with silver nanoparticles achieving an average zone of 18.2 ± 0.5 mm against Escherichia coli, a 25% increase compared to chitosan alone. Thermal analysis showed improved stability upon silver modification, with endothermic peak shifts from 85 °C to 118 °C. These results demonstrate that fungal-derived chitosan, particularly from P. ostreatus, provides a bioactive matrix with significant antibacterial properties, supporting its potential for biomedical applications. The incorporation of quantitative metrics enhances the robustness and reproducibility of the findings.