One-Step Sodium Bisulfate Hydrolysis for Efficient Production of Xylooligosaccharides from Poplar

Abstract

Acid salts have been shown to selectively and efficiently catalyze xylan hydrolysis for the generation of xylooligosaccharides (XOS), while using acid salts that are non-toxic and available as feed additives can avoid separation from resulting XOS-rich hydrolysate. Currently, there is no report on XOS production by hydrolysis with sodium bisulfate (NaHSO4), of significance is that NaHSO4 as feed additive without need for separation. In this work, NaHSO4 hydrolysis was firstly employed to produce XOS from poplar. The XOS yield of 42.7% was reached under optimal conditions. After hydrogen peroxide/acetic acid and sodium hydroxide treatment of NaHSO4-pretreated poplar, high yields of glucose (92.0%) and xylose (91.3%) were obtained at a low cellulase dose of 5 FPU/g dry mass. This work suggests that NaHSO4 hydrolysis is a novel strategy to prepare XOS from poplar efficiently with simple operation steps, and XOS-rich hydrolysates could be potentially used as feed additive without NaHSO4 separation.

Keywords: Xylooligosaccharides, Sodium bisulfate, Hydrogen peroxide/acetic acid, Sodium hydroxide, Monosaccharides