Intracellular Oxygen-metabolizing Enzymes of Phanerochaete chrysosporium

SUMMARY: The levels of catalase and superoxide dismutase present in the white-rot fungus Phanerochaete chrysosporium were investigated. The specific activities of both enzymes increased and reached a maximum after 4-6 d growth before falling to a constant low activity. Catalase was purified and found to be the typical eukaryotic enzyme. Activity staining, in the presence and absence of cyanide, revealed that the cytosol of P. chrysosporium contained only the copper/zinc superoxide dismutase commonly found in eukaryotes. These results show that P. chrysosporium meets the challenge of raised levels of activated oxygen by producing enhanced levels of the usual detoxifying enzymes rather than any novel isoenzymes.