White-rot fungus, P. ostreatus (Jacq.: Fr.) Kummer (type: Florida;ATCC No. MYA-2306) was maintained at 4◦C through periodic transfer on potato dextrose agar (Difco) plates in the presence of 0.5% yeast extract. Mycelia were inoculated in 1 L flasks con-taining 500 mL of potato-dextrose broth (24 g/L) supplemented with 0.5% yeast extract,