Toxicity and decomposition activity inhibition of VO2 micro/nanoparticles to white rot fungus Phanerochaete chrysosporium

Abstract

Vanadium dioxide (VO₂) is an excellent phase transition material widely used in various applications, and thus inevitably enters the environment via different routes and encounters various organisms. Nonetheless, limited information is available on the environmental hazards of VO₂. In this study, we investigated the impact of two commercial VO₂ particles, nanosized S-VO₂ and micro-sized M-VO₂ on the white rot fungus Phanerochaete chrysosporium. The growth of P. chrysosporium is significantly affected by VO₂ particles, with S-VO₂ displaying a higher inhibitory effect on weight gain. In addition, VO₂ at high concentrations inhibits the formation of fungal fibrous hyphae and disrupts the integrity of fungus cells as evidenced by the cell membrane damage and the loss of cytoplasm. Notably, at 200 μg/mL, S-VO₂ completely alters the morphology of P. chrysosporium, while the M-VO₂ treatment does not affect the mycelium formation of P. chrysosporium. Additionally, VO₂ particles inhibit the laccase activity secreted by P. chrysosporium, and thus prevent the dye decoloration and sawdust decomposition by P. chrysosporium. The mechanism underlying this toxicity is related to the dissolution of VO₂ and the oxidative stress induced by VO₂. Overall, our findings suggest that VO₂ nanoparticles pose significant environmental hazards and risks to white rot fungi.