Comparison of polyol-based deep eutectic solvents (DESs) on pretreatment of moso bamboo (Phyllostachys pubescens) for enzymatic hydrolysis

Abstract

Four polyol-based deep eutectic solvents (DESs) were designed for bamboo pretreatment and enzymatic hydrolysis , and the pretreatment conditions including temperature, time and acid dosage in the optimized DES were comprehensively evaluated. The results showed that the components separation and saccharification of bamboo could be promoted by polyol-based DESs pretreatment, which are positively correlated with the hydroxyl contents of hydrogen bond donor in DESs, except for sorbitol-based DES. Excessive hydroxyl contents could lead to the increase of DES viscosity and lignin deposition, which had a negative effect on saccharification. Meanwhile, the optimum pretreatment conditions in xylitol-based DES (ChCl/XL) were determined to be 120 °C for 3 h with 1wt% acid, and 96.08% of glucose yield was recorded. The recycling experiment indicated that ChCl/XL retained acceptable pretreatment performance. This work gives novel insights into the design and selection of polyol-based DES for bamboo pretreatment and enzymatic hydrolysis. • A novel insights into polyol DES pretreatment was designed for enzymatic hydrolysis. • The optimum pretreatment solvent is xylitol-based DES (ChCl/XL). • ChCl/XL can be adjusted by adding acid to keep its capability after multiple cycles. • Glucose yield was 96.08% at the optimal condition (120 °C, 3 h, 1wt% acid).