Exploring surface properties of substrate to understand the difference in enzymatic hydrolysis of sugarcane bagasse treated with dilute acid and sulfite

The sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) is beneficial to subsequent enzymatic hydrolysis. In this study, to elucidate enzymatic hydrolysis mechanism of SPORL treated sugarcane bagasse (SCB), the surface properties of SPORL and dilute acid (DA) treated SCBs were compared, including cellulase adsorption isotherm and kinetics, specific surface area and average size of pores, water retention value (WRV), element composition and percentages of different chemical bonds on the substrate surface. The results showed the hydrolysis yield of SPORL SCB (76.16 %) was higher than that of DA (57.82 %) and SPORL SCB had better adsorption capacity, lower binding strength, a higher cellulase adsorption rate, larger specific surface area and higher WRV, and these two SCBs might adsorb cellulase by C-OR bonds (R: organic groups), suggesting SPORL SCB's surface was more advantageous to enzymatic hydrolysis. This study could help understand the mechanism of lignocellulosic hydrolysis in depth.