Study of alkaline hydrogen peroxide pretreatment and enzymatic hydrolysis of bamboo

This study pretreated bamboo with alkaline hydrogen peroxide (AHP), the effects of hydrogen peroxide concentration on chemical composition and enzymatic digestibility were investigated. The physical and chemical structural variations of the samples before and after the pretreatment were studied with X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), and the chemical structure of residual lignins in pretreated bamboo were investigated by 2D-HSQC NMR spectroscopy. The results indicate that in the process of alkaline hydrogen peroxide pretreatment, with the increase of H2O2 dosage, the glucan content of bamboo first increases and then decreases, while the contents of xylan remains basically unchanged, and the lignin content shows a decreasing trend after the AHP pretreatment. The AHP pretreatment improves the enzymatic digestibility of bamboo, and the enzymatic hydrolysis yield reaches the maximum of 93.9% (glucan) and 100% (xylan) when the cellulase dosage is 15 FPU/g glucan and H2O2 dosage is 7.0%. The lignin removal rate plateau at the 2.0% H2O2, with a delignification of ~68% (2.0% H2O2). The 2D-HSQC NMR was performed to reveal the chemical structure of the residual lignin in the pretreated bamboo sample, it is found that the chemical structure of the undegradable residual lignin contains 64% S units, 33.7% G units and 61.6% β-O-4 bonds with the S/G value of 1.90. © 2022, Solar Energy Periodical Office Co., Ltd. All right reserved.