Crystallinity of cellulose, degree of polymerization, moisture
content, available surface area, and lignin content are factors that
hinder the attack of enzymes. For these reasons, suitable pretreatment
is necessary to successfully hydrolyze lignocellulosic
biomass with enzymes. An effective pretreatment is characterized
by several criteria. It should avoid the need to reduce the size of
biomass particles, preserve the pentose (hemicellulose) fractions,
limit formation of the degradation products that inhibit the growth
of fermentative microorganisms, minimize energy demands and
limit costs. Additionally, the pretreatment agent should have low
cost and be capable of inexpensive recycling (Binod et al., 2012).