Present Status On Enzymatic Hydrolysis of Lignocellulosic Biomass for Bioethanol Production

Abstract

Bioethanol is becoming a better alternative to fossil fuels. Production of ethanol by using edible feedstock such as grains, sugarcane etc., became a point of concern in terms of the food supply and demand. In such a scenario lignocellulosic biomass that includes nonedible feedstocks opened up a new avenue for the second- generation bioethanol production. Lignocellulosic bioethanol production is composed of three major steps: pretreatment, enzymatic hydrolysis and fermentation. The main factor restraining the commercialization of bioethanol lies in the development of the enzymatic hydrolysis step. During the enzymatic hydrolysis step carbohydrates (cellulose and hemicelluloses) polymers get converted into free monomeric sugars. The major problems associated with enzymatic hydrolysis are cost of the enzyme, higher incubation time for complete degradation of carbohydrates, inhibition of enzyme activity in the presence of phenolic compounds and thermal inactivation of cellulase enzyme. The present article discusses recent trends and development of the enzymatic hydrolysis process for cost-effective bioethanol production. In this review the authors cover the following points: development of cellulase-producing organisms, the enzyme production process