1. Introduction
Agricultural, agro-industrial and forestry lignocellulosic
residues have potential as cheap and renewable feedstocks for
large-scale production of fuels and chemicals. Currently, bioprocessing
of lignocellulosics is focused on enzymatic hydrolysis
of the cellulose fraction to glucose, followed by fermentation
to fuel-grade ethanol. However, enzymatic hydrolysis of cellulosic
materials to produce fermentable sugars has also enormous
potential in meeting global food and energy demand via biological
route [1].
Enzymatic hydrolysis of cellulose is a reaction carried out by
cellulase enzymes, which are highly specific [2]. Cellulases are
usually a mixture of several enzymes, among which at least three
major groups are involved in the hydrolysis process of cellulose:
(1) -1-4-endoglucanase (EC 3.2.1.4.), which attacks regions of