Bacterial GH10 Endoxylanase-Driven Enhanced Saccharification of Rice and Wheat Straw

Modern agriculture generates large amounts of straw, thus posing significant residue management challenges. In this context, traditional disposal methods such as residue incineration can cause severe environmental harm. From a circular economy perspective, rice and wheat straw are valuable lignocellulosic resources from which high-value bioproducts can be derived, including xylooligosaccharides (XOS). Efficient conversion of this biomass depends on the enzymatic degradation of xylan, the main hemicellulose in cereal straw. In this study, four GH10 endoxylanases were evaluated, of which X11 and its hybrid variant X11C2 showed the best performance, particularly at pH 9.0. X11 showed robustness under harsh conditions and a tendency to release short sugars such as xylose and xylobiose. Both rice and wheat straw exhibited partial saccharification, but wheat straw released higher amounts of soluble sugars, indicating a higher susceptibility to enzymatic hydrolysis. Given the growing interest in XOS as prebiotics with multiple health benefits, the enzymatic hydrolysis of low-cost agricultural residues—supported by appropriate pretreatment—represents a promising and sustainable strategy for XOS production.