A review on xylanase sources, classification, mode of action, fermentation processes, and applications as a promising biocatalyst.

The utilization of hydrolytic enzymes in various industrial processes worldwide has gained more attention than chemical catalysts due to the high selectivity of enzymes, their ease of control, and their negligible environmental impact, as they produce very small amounts of byproducts. Xylanase is one such enzyme that catalyzes the breakdown of the β-1,4 linkage of xylan, the second most abundant renewable heteropolysaccharide and hemicellulosic constituent of the plant cell wall. Naturally, xylanase can be obtained from various sources such as mollusks, insects, plants, animals, and various microorganisms (bacteria, fungi, yeast, and algae). The utilization of xylanase could greatly improve the overall economics of processing lignocellulosic materials for the generation of monosaccharides, liquid fuels, and chemicals. Microbial xylanase is suitable for applications in food and feed, paper and pulp, textile, pharmaceutical, and biorefining industries. It has gained global attention due to its substrate specificities, biochemical properties, and various biotechnological applications. This review focuses on xylanase production, sources, fermentation processes, modes of action, purification methods, and applications in various industries.