Chitinase

Abstract

Chitinases are glycosyl hydrolases with sizes ranging from 20 kDa to about 90 kDa. They are present in a wide range of organisms such as bacteria, fungi, yeasts, plants, actinomycetes, arthropods, and humans. Chitinases can degrade chitin directly to low molecular weight chitooligomers, which serve a broad range of industrial, agricultural, and medical functions such as elicitor action and anti-tumor activity. Chitin, a linear polymer of β-1, 4-N-acetylglucosamine (GlcNAC), is the second most abundant biopolymer on the planet. Chitin is found in the outer skeleton of insects, fungi, yeasts, algae, crabs, shrimps, and lobsters, and the internal structures of other invertebrates. Chitinases are a huge and diverse group of enzymes that show differences in their molecular structure, substrate specificity, and catalytic mechanism. It is vital to study the substrate specificity of chitinases as it not only reveals the relationship between the substrate specificity and physiological roles but also allows one to degrade chitin into novel products having industrial applications. Chitin is the second most abundant polysaccharide after cellulose and is mostly found in the cell wall of fungi, yeast, exoskeletons of insects, and crustacean shells. There has been a steady increase in demand for chitin derivatives, obtained by the action of chitinases on chitin polymer for various industrial, clinical, and pharmaceutical purposes. Hence, this chapter focuses on the properties and applications of chitinases.