Extracellular enzyme production by three Pleurotus ostreatus strains at different stages of the cultivation cycle.

Extracellular enzyme production [carboxymethyl cellulase(CMCase),filter paper cellulase(FPase),amylase,protease,xylanase,laccase and peroxidase] by three strains of Pleurotus ostreatus(Xin831,Hei Pingwang and Heiping-5) was determined at different stages of the cultivation cycle.CMCase,FPase,xylanase,amylase and protease levels were relatively low during the mycelium growth phase,and peak activities of these enzymes were recorded at the fruit body maturation stage.Highest laccase and peroxidase activities were recorded when the fungal mycelia had fully colonized the growth substrate.Enzyme levels then gradually decreased although a second,smaller,peak of activity was observed during the interval between the first and second flushes.