Mycelial growth of three Pleurotus (Jacq.: Fr.) P. Kumm. species on sugarcane bagasse:: Production of hydrolytic and oxidative enzymes

The present study is based on the mycelial growth of 37 Pleurotus strains, belonging to P. djamor, P. ostreatus, and P. pulmonarius species. The strains were grown on sugarcane bagasse, using 2 kinds of inoculation: (1) spawn prepared on wheat seeds, and (2) mycelium grown within solid water-agar culture with no nutrients added. Based on differences found in the mycelial growth, 6 strains were selected to determine the production of certain hydrolytic and oxidative enzymes throughout the full growth cycle at 0, 4, 8, 12, and 16 days (incubation period), also including the primordia formation, fruiting, and postharvest stages. The production of laccase and Mn-peroxidase was clear during the incubation stage, decreased during the fruiting stage, and increased again during the postharvest stage. In addition, the production of cellulases, cellobiohydrolases, and xylanases was low during the incubation period, increased during the production of fruiting bodies, and declined during the postharvest. There was a visible inverse correlation between the content of soluble phenols of the substrate and the laccase production at 8 (r = -.85) and 12 (r = -.92) incubation days. The incubation period varied between 12 and 45 days among the studied strains. Their biological efficiency was generally good, with values between 65.3% and 118.8%.