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

Vanadium dioxide (VO) 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 VO. In this study, we investigated the impact of two commercial VO particles, nanosized S-VO and micro-sized M-VO on the white rot fungus Phanerochaete chrysosporium. The growth of P. chrysosporium is significantly affected by VO particles, with S-VO displaying a higher inhibitory effect on weight gain. In addition, VO 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-VO completely alters the morphology of P. chrysosporium, while the M-VO treatment does not affect the mycelium formation of P. chrysosporium. Additionally, VO 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 VO and the oxidative stress induced by VO. Overall, our findings suggest that VO nanoparticles pose significant environmental hazards and risks to white rot fungi.