Lignocellulosic biomass has been projected to be one of the
main resources for economically attractive bioethanol production.
Though theoretical ethanol yields from sugar and starch (g ethanol/
g substrate) are higher than from lignocellulose, these conventional
sources are insufficient for worldwide bioethanol production. In
that aspect agricultural wastes are renewable, less costly and
abundantly available in nature. Agricultural wastes do not demand
separate land, water, and energy requirements. They do not have
food value as well. For economically feasible bioethanol production,
several hindrances are to be overcome. These refer to the four major
aspects which are feedstock, conversion technology, hydrolysis
process, and fermentation configuration. With regard to feedstock
major obstacles are cost, supply, harvesting, and handling. As
regards conversion technology the hindrances are biomass processing,
proper and cost effective pretreatment technology to
liberate cellulose and hemicellulose from their complex with lignin.
In respect of the hydrolysis process the challenge is to achieve an
efficient process for depolymerization of cellulose and hemicellulose
to produce fermentable monomers with high concentration.
In this aspect enzymatic hydrolysis may be the most potent
alternative process for saccharification of complex polymer. Several