Physicochemical properties of pretreated biomass believed to affect cellulose digestibility
• A key factor for sucessful enzymatic conversion of biomass to fermentable sugars is the accessibility of the β-(1-4) glycosidicbonds in cellulose to cellulase enzymes.
• Pretreatment regimes must be designed to remove substrate-specific barriers to cellulases to improve cellulose digestion.
• The precise nature of the obstacles encountered by cellulases in the complex biomass ultra-structure remains ambiguous.
• The effect of pretreatment is typically evaluated on the basis of improved enzyme digestibility and downstream ethanol production.
• The link between changes in cell wall chemistry/structure and cellulase digestibility is ultimately dependent on improved access to the cellulose microfibril.
• Some factors that could influence the rate of enzymatic hydrolysis of cellulose in pretreated lignocellulosic biomass are cellulose crystallinity, degree of cellulose polymerization, feedstock particle size, the lignin barrier (content and distribution), substrate available surface area (pore volume), and cell wall thickness (coarseness).
• Typical physiochemical properties of biomass obtained from the pretreatments are shown in Table 1.