Structures, Biochemical Characteristics, and Functions of beta-Xylosidases

The complete degradation of abundant xylan derived from plants requires the participation of beta-xylosidases to produce the xylose which can be converted to xylitol, ethanol, and other valuable chemicals. Some phytochemicals can also be hydrolyzed by beta-xylosidases into bioactive substances, such as ginsenosides, 10-deacetyltaxol, cycloastragenol, and anthocyanidins. On the contrary, some hydroxyl-containing substances such as alcohols, sugars, and phenols can be xylosylated by beta-xylosidases into new chemicals such as alkyl xylosides, oligosaccharides, and xylosylated phenols. Thus, beta-xylosidases shows great application prospects in food, brewing, and pharmaceutical industries. This review focuses on the molecular structures, biochemical properties, and bioactive substance transformation function of beta-xylosidases derived from bacteria, fungi, actinomycetes, and metagenomes. The molecular mechanisms of beta-xylosidases related to the properties and functions are also discussed. This review will serve as a reference for the engineering and application of beta-xylosidases in food, brewing, and pharmaceutical industries.