Production of prebiotic-xylooligosaccharides from alkali pretreated mahogany and mango wood sawdust by using purified xylanase of Clostridium strain BOH3

Abstract

Xylooligosaccharides (XOS) are emerging prebiotics which can be produced from lignocellulosic biomass including agro-residues and hardwood. In this study, we report the production of XOS from thermal-alkali pretreated hardwood such as mahogany and mango by using a purified xylanase from Clostridium strain BOH3. In the first approach, pure xylan is extracted from mahogany and mango hardwood and then the pure xylan is hydrolyzed by using the xylanase. In this case, 572 and 504mg XOS/g pure xylan were obtained from mahogany and mango woods, respectively. In the second approach, the same xylanase is employed to hydrolyze sawdust of hardwood after different types of pretreatments. After a thermal (121°C for 15min) pretreatment under a mild alkaline (0.05N NaOH) condition, the pretreated mahogany and mango sawdust can be utilized directly to produce 89.5 and 67.6mg XOS/g pretreated sawdust, respectively. XOS produced from the pretreated sawdust show strong prebiotic effects on Bifidobacteria and Lactobacilli. This report shows the possibility of producing XOS from pretreated woody wastes without using pure xylan as a substrate.