Dual effects of lignin derivatives produced by hydrothermal pretreatment on cellulase hydrolysis

Efficient enzymatic hydrolysis of lignocellulosic biomass is crucial for the development of non-food biofuels, but the efficiency is often hindered by the inhibitory interactions between cellulase and lignin. In this study, pseudo-lignin (PL) and lignin-like substances (LL) were extracted from hydrothermal pretreated residues and liquid, respectively, and the interactions between these lignin derivatives and cellulase were thoroughly studied. The results showed that PL had extremely strong hydrophilicity, which significantly increased the α-helix content of cellulase, thereby facilitating the improvement of enzymatic hydrolysis. In contrast, LL exhibited inhibitory effects on cellulase activity under hydrophobic interactions. From this, it can be seen that PL is beneficial for enzymatic hydrolysis and is not affected by the pretreatment severity and raw materials. This new perspective will provide a new insight for the combination of hydrothermal pretreatment and enzymatic hydrolysis technology.