Spent substrate, the residual material of mushroom cultivation, causes disposal problems for
cultivators. Currently the spent substrate of different mushrooms is used mainly for composting. Edible
mushrooms of Pleurotus sp. can grow on a wide range of lignocellulosic substrates. In the present study,
Pleurotus eous was grown on paddy straw and the spent substrate was used for the production of ethanol.
Lignocellulosic biomass cannot be saccharified by enzymes to high yield of ethanol without pretreatment. The
root cause for the recalcitrance of lignocellulosic biomass such as paddy straw is the presence of lignin and
hemicelluloses on the surface of cellulose. They form a barrier and prevent cellulase from accessing the
cellulose in the substrate. In the untreated paddy straw, the amount of hemicelluloses and lignin (in % dry
weight) were 20.30 and 20.34 respectively and the total reducing sugar was estimated to be 5.40 mg/g.
Extracellular xylanase and ligninases of P. eous could reduce the amount of hemicelluloses and lignin to 16 and
11(% dry weight) respectively, by 21st day of cultivation. Growth of mushroom brought a seven fold increase in
the total reducing sugar yield (39.20 mg/g) and six fold increase in the production of ethanol (6.48 g/L) after
48hrs of fermentation, when compared to untreated paddy straw
Description:
International Journal of Applied Biology and Pharmaceutical Technology,vol 3,issue 1:jan-mar 2012