Biocatalyst systems for xylooligosaccharides production from lignocellulosic biomass and their uses

Abstract The conversion of lignocellulosic residues into value-added products has gained prominence due to the range of economically important biomolecules that can be obtained thereof. One example is xylooligosaccharides (XOS), which are nontoxic and nondigestable oligosaccharides made of 2–6 xylose units. They can be produced from agricultural crop residues that are mainly constituted of cellulose, hemicellulose, and lignin. Among hemicelluloses, xylan is the most common. XOS can be obtained through xylan hydrolysis by endo-β-1,4-xylanases action. The use of enzymes is preferred among other methods, such as acid hydrolysis, due to their high efficiency and specificity that allow better control of the degree of polymerization and avoid by-products formation. XOS present interesting prebiotic effects, by stimulating the growth of beneficial intestinal bacteria, and can be used as a supplement or incorporated into many human food products. This chapter covers XOS production and enzymes involved in the process, extraction sources and their structures, biological application, purification, and market.