Effect of lignin isolated from p-toluenesulfonic acid pretreatment liquid of sugarcane bagasse on enzymatic hydrolysis of cellulose and cellulase adsorption

During lignocellulosic enzymatic hydrolysis, lignin is generally considered negative. To investigate the relation between lignin profiles and the effect of lignin on hydrolysis, in this study, the enzymatic hydrolysis efficiency and cellulase adsorption amount of Avicel and PB (p-toluenesulfonic acid (p-TsOH) treated sugarcane bagasse) were firstly determined before and after adding the p-TsOH lignin (isolated lignin from PB). Subsequently, the particle size, crystallinity, hydrogen bonds, electrostatic charges and hydrophobicity of PB and Avicel, and the chemical bonds of p-TsOH lignin were measured. The results indicated that adding the p-TsOH lignin inhibited Avicel's hydrolysis, but increased the cellulase adsorption. This might be because after adding p-TsOH lignin, the lignin adsorbed more cellulase and the cellulase molecules on Avicel decreased. For PB, adding the p-TsOH lignin reduced the cellulase adsorption, but did not impact the hydrolysis efficiency. This might be due to the decrease in non-productive adsorption of cellulase.