Biodegradation of wheat straw by Pleurotus ostreatus

Abstract

Wheat straw pretreated with chemicals as well as hot water was subjected to degradation by edible mushroom Pleurotus ostreatus. Lignin, cellulose and hemicelluloses component of both chemically as well as hot water treated wheat straw was degraded by the fungus and in turn the edible and nutritious fruiting body of the mushroom was produced. Biodegradation of wheat straw in terms of loss of lignin, cellulose and hemicellulose showed positive correlation with cellulases, xylanase, laccase and polyphenol oxidase (PPO) activity of the fungus. During vegetative growth of the fungus, lignin degradation was faster and during fructification, lignin degradation was slower than cellulose and hemicellulose. The carbon content of the wheat straw decreased while, nitrogen content increased during degradation of the waste. Hot water treated wheat straw supported better production of enzymatic activity and degraded more efficiently than chemically sterilized substrate. The cumulative yield and biological efficiency (BE) of the mushroom was maximum on the hot water treated substrate. Degradation of the hot water treated wheat straw was better and faster than chemically treated substrate.