This study reported that glycine promoted S-type lignin removal via strong hydrogen bonding interactions (confirmed by the 13C NMR upfield shift) while suppressing cellulose degradation by competing for cellulose hydroxyl sites. Efficient pretreatment of corn straw was achieved at 25 wt % solids loading using BmimDCA-Gly system, attaining 78.11% delignification. Pretreatment converted the straw surface from dense to loose and porous, with β-O-4 cleavage inducing lignin depolymerization. The regenerated lignin had an elevated S/G ratio and contained PhGlc linkages. The cellulose recovery rate was 95.45%. With 5 FPU/g enzyme loading, the saccharification yield reached 95.69%, 2.75 times that of untreated material. The BmimDCA-Gly system was successfully recycled four times while maintaining high cellulose recovery and saccharification efficiency, providing a green strategy for biomass pretreatment.
Yang et al. (Wed,) studied this question.