Study on the Cytotoxicity of Silver Nanoparticles in the Ligninolytic Fungus Phanerochaete chrysosporium

Silver nanoparticles (AgNP), which have a wide range of applications in technical and biological fields, are produced in hundreds of tons annually and are eventually released into water, air, and soil. In this study, the effects of AgNPs on Phanerochaete chrysosporium, a white-rot fungus that plays a key role in wood waste degradation, were investigated. The AgNP were synthesized at high temperature with gallic acid under different pH conditions: near-neutral pH (~7.5), notation AgNP@GA-1, and alkaline pH (~10.5), notation AgNP@GA-2, focusing on their ability to cope with oxidative stress. The samples were characterized by fine granularity (particle diameter of 12 and 11 nm, respectively), specific plasmonic features (characteristic band at 425 and 408 nm), hydrodynamic diameter of 93 and 133 nm, respectively, and Zeta potential of −34 to −44 mV, which gave them stability over a period of three months. The fungal cultures exposed to AgNP concentrations of 40–100 µL/mL (approximately 4–11 µg/mL) presented superoxide dismutase (SOD) activity, which increased by approximately 45% at 40 µL/mL for AgNP@GA-1 after 7 days, whereas AgNP@GA-2 decreased SOD activity by up to 40% at 60 µL/mL. Both AgNP types strongly stimulated catalase (CAT) biosynthesis, with two- to three-fold increased activity on the 7th day at 100 µL/mL. CAT activity remained significantly elevated for AgNP@GA-1 on the 14th day at 60–80 µL/mL, whereas for AgNP@GA-2 it decreased by 40–60% compared with the control. Variations in malondialdehyde content indicated moderate lipid peroxidation, suggesting relatively low cytotoxic effects on fungal cells. Overall, the results demonstrate that P. chrysosporium exhibits adaptive biochemical responses to AgNP-induced oxidative stress while maintaining metabolic functionality, highlighting the potential compatibility of AgNPs with white-rot fungi involved in environmental wood waste biodegradation processes.