Effect of ultrasound-assisted xylanase pretreatment on the soluble substances of poplar wood and its model construction

Cellulose, hemicellulose, and lignin molecules in poplar wood are interwoven to form a dense network-like structure, which prevents their degradation into oligomers for the preparation of biomass-based materials and chemicals. Therefore, it is necessary to use a pretreatment process to decompose the complex matrix. In this study, ultrasound-assisted xylanase treatment was used for poplar wood pretreatment. The effects of different parameters, such as enzyme treatment time, enzyme dosage, and ultrasound time on soluble substances and the surface of the cell wall were systematically investigated. The optimal conditions for the degradation of hemicellulose and lignin in poplar wood were a treatment time of 60 min and a xylanase dosage of 25 U/g. Ultrasound-assisted xylanase treatment improved the efficiency of removing hemicellulose. The contents of glucose, xylose, and lignin were increased by 34.73%, 32.01%, and 59.65%, respectively, with the ultrasound-assisted xylanase treatment. In addition, a least-squares model was constructed to describe the dissolution behavior of component, which is helpful to guide the subsequent conversion and utilization of poplar wood biomass.