Demonstrating the synergistic impact of sodium lignosulfonate in dilute acid pretreatment and enzymatic hydrolysis of poplar sawdust

Sodium lignosulfonate (LS) is typically the primary industrial lignin derived from pulping process. Owing to LS’s surface-active properties, this work employed it in conjunction with pretreatment and enzymatic hydrolysis to biotransform poplar sawdust (PS). The findings revealed that a pretreatment of PS using 40 g/L LS and 4 g/L H 2 SO 4 (LSPS) led to the separation of 49.7 % lignin and 80.5 % xylan, consequently increasing the enzymatic hydrolysis efficiency (EHE) from 22.4 % to 66.9 %. Furthermore, an EHE of 72.8 % was achieved with 5 g/L LS, while an EHE of 71.7 % was obtained with the prehydrolysate (20 g/L LS) contained in enzymatic hydrolysis. Analysis indicated that the elevated EHE of LSPS was ascribed to enhanced accessibility and reduced surface area of lignin on one hand, and increased enzymatic activity through LS’s electrostatic adsorption on the other hand. These results underscored the high-value utilization of lignin-based surfactants in both pretreatment and enzymatic hydrolysis processes.