Responses of <i>Phanerochaete chrysosporium</i> to Toxic Pollutants: Physiological Flux, Oxidative Stress, and Detoxification

The white-rot fungus <i>Phanerochaete chrysosporium</i> has been widely used for the treatment of waste streams containing heavy metals and toxic organic pollutants. The development of fungal-based treatment technologies requires detailed knowledge of the relationship between bulk water quality and the physiological responses of fungi. A noninvasive microtest technique was used to quantify real-time changes in proton, oxygen, and cadmium ion fluxes following the exposure of <i>P. chrysosporium</i> to environmental toxic (2,4-dichlorophenol and cadmium). Significant changes in H⁺ and O₂ flux occurred after exposure to 10 mg/L 2,4-dichlorophenol and 0.1 mM cadmium. Cd²⁺ flux decreased with time. Reactive oxygen species formation and antioxidant levels increased after cadmium treatment. Superoxide dismutase activity correlated well with malondialdehyde levels (r² = 0.964) at low cadmium concentrations. However, this correlation diminished and malondialdehyde levels significantly increased at the highest cadmium concentration tested. Real-time microscale signatures of H⁺, O₂, and Cd²⁺ fluxes coupled with oxidative stress analysis can improve our understanding of the physiological responses of <i>P. chrysosporium</i> to toxic pollutants and provide useful information for the development of fungal-based technologies to improve the treatment of wastes cocontaminated with heavy metals and organic pollutants