Enhancing enzymatic hydrolysis of masson pine by sulfuric acid catalyzed γ-valerolactone synergistic pretreatment under a lignin-first strategy

Developing green pretreatment technologies that prioritize the selective separation of lignin is of significant importance for the industrialization of biorefining. This work employed H 2 SO 4 -catalyzed γ-valerolactone (GVL) pretreatment on masson pine sawdust (GAM) to investigate process conditions and the enzymatic hydrolysis performance of masson pine. The results indicated that the lignin removal rate was 87.2% under the optimal pretreatment conditions (150ºC, 75 mM H 2 SO 4 ). The synergistic effect of the H 2 SO 4 catalyst and GVL pretreatment resulted in an enzymatic hydrolysis yield for GAM (76.8%) nearly six times higher than that of other non-synergistic systems (5.7%∼13.0%). Furthermore, the enzymatic hydrolysis yield increased to 97.3% upon the addition of bovine serum albumin . Microscopic visualization was used to analyze the morphological changes of cells and the micro-distribution of lignin within GAM cell walls after pretreatment. Additionally, structural changes in the molecular weight , functional groups, and linkage contents of GAM lignin were analyzed. This research provides valuable insights for masson pine in producing fermentable monosaccharides and acquiring lignin with enhanced processing properties.