Effect of cadmium on the ligninolytic activity of Stereum hirsutum and Phanerochaete chrysosporium

An inhibitory effect of cadmium on the growth and ligninolytic activity of the wood-rotting basidiomycetes Phanerochrete chrysosporium, Pleurotus ostreatus, Pycnoporus cinnabarinus and Stereum hirsutum was observed. Delayed decolorization of the polymeric dye Poly R-478 was observed in samples with 0.10 mmol/L Cd. Addition of 0.25 mmol/L Cd to the cultivation medium strongly reduced the activity of both Mn-dependent and Mn-independent peroxidases of Stereum hirsutum, while the activity of laccase was not affected to a similar extent. The maximum of MnP activity in these samples was found during the exponential phase of growth whereas control samples showed the highest activity after the onset of the stationary phase (days 15-21). Cadmium at concentrations higher than 0.50 mmol/L significantly inhibited the activity of all enzymes tested in both S. hirsutum and P. chrysosporium.