Bioethanol is a liquid fuel obtained from fermentation of sugar/starch crops. Lignocellulosic
biomass being less expensive is considered a future alternative for the food crops. One of the main
challenges for the use of lignocellulosics is the development of an efficient pre-treatment process.
Pretreatments are classified into three - physical, chemical, and biological pretreatment. Chemical process
has not been proven suitable so far, due to high costs and production of undesired by-products.
Biologically, hydrolysis can be enhanced by microbial or enzymatic pretreatment. Studies show that the
edible mushrooms of Pleurotus sp. produce several extracellular enzymes which reduce the structural and
chemical complexity of fibre. In the present study, P. ostreatus and P. eous were cultivated on paddy straw.
Spent substrate left after mushroom cultivation was powdered and used for ethanol production.
Saccharomyces sp. was used for fermentation studies. Untreated paddy straw was used as control.
Production of ethanol from P. ostreatus substrate was 5.5 times more when compared to untreated paddy
straw, while the spent substrate of P. eous gave 5 times increase in ethanol yield. Assays showed the
presence of several extracellular enzymes in the spent substrate of both species, which together contributed
to the increase in ethanol yieldCochin University of Science and
TechnologyInternational Journal of Plant, Animal and Environmental Sciences,vol 2,issue 2,april-june 201
