Xylo-oligosaccharides(XOSs)are a category of functional oligosaccharides primarily composed of 2-7 xylose units linked byβ-1,4 glycosidic bonds.They are recognized as soluble dietary fibers with prebiotic properties....Xylo-oligosaccharides(XOSs)are a category of functional oligosaccharides primarily composed of 2-7 xylose units linked byβ-1,4 glycosidic bonds.They are recognized as soluble dietary fibers with prebiotic properties.Recently, there has been significant interest in manufacturing XOSs from xylan extracted from lignocellulosic biomass using enzyme catalysis under mild conditions. In this work, the arabinofuranosidase Abf62A gene was cloned from Aspergillus usamii genomic DNA through sequential molecular processes and expressed in Pichia pastoris X33. The xylan (100 g/L) extracted xylan in wheat straw (WS) was biologically hydrolyzed into 50.32 g/L of XOSs by xylanase Xyn11A (300 U/g substrate) and arabinofuranase Abf62A (20 U/g substrate), which indicated a notable synergistic effect compared to the 34.42 g/L XOSs produced via Xyn11A. The 50.32 g/L of XOSs products comprised xylobiose (31.71 g/L), xylotriose (15.92 g/L), xylotetraose (1.65 g/L) and xylopentaose (1.04 g/L). Notably, the combined content of xylobiose and xylotriose accounted for up to 94.7%. The XOSs purified from the enzyme hydrolysate could effectually scavenge free radicals, and the antioxidant activity was more than 90%. In summary, XOSs were biologically manufactured from wheat straw xylan through the synergistic biocatalysis via xylanase and arabinofuranosidase Abf62A in a green and sustainable way, rending one kind of prebiotic oligosaccharides with substantial positive effects on human and animal health.展开更多
文摘Xylo-oligosaccharides(XOSs)are a category of functional oligosaccharides primarily composed of 2-7 xylose units linked byβ-1,4 glycosidic bonds.They are recognized as soluble dietary fibers with prebiotic properties.Recently, there has been significant interest in manufacturing XOSs from xylan extracted from lignocellulosic biomass using enzyme catalysis under mild conditions. In this work, the arabinofuranosidase Abf62A gene was cloned from Aspergillus usamii genomic DNA through sequential molecular processes and expressed in Pichia pastoris X33. The xylan (100 g/L) extracted xylan in wheat straw (WS) was biologically hydrolyzed into 50.32 g/L of XOSs by xylanase Xyn11A (300 U/g substrate) and arabinofuranase Abf62A (20 U/g substrate), which indicated a notable synergistic effect compared to the 34.42 g/L XOSs produced via Xyn11A. The 50.32 g/L of XOSs products comprised xylobiose (31.71 g/L), xylotriose (15.92 g/L), xylotetraose (1.65 g/L) and xylopentaose (1.04 g/L). Notably, the combined content of xylobiose and xylotriose accounted for up to 94.7%. The XOSs purified from the enzyme hydrolysate could effectually scavenge free radicals, and the antioxidant activity was more than 90%. In summary, XOSs were biologically manufactured from wheat straw xylan through the synergistic biocatalysis via xylanase and arabinofuranosidase Abf62A in a green and sustainable way, rending one kind of prebiotic oligosaccharides with substantial positive effects on human and animal health.
