ABSTRACT
Pullulan-degrading enzymes, known as pullulanase, break the polymer to smaller oligomers, hydrolyzing glycoside linkages. In this chapter, the authors discuss different types of pullulanase, their origin, and some common biochemical features with special reference to substrate-binding domains. An attempt has been made to present different mechanisms proposed from time to time on enzymatic degradation of pullulan. Thus, pullulan-degrading enzymes have the ability to hydrolyze these glycosidic linkages. The active sites of all the different types of pullulanases have similar crystal structure as well as the active site with Glu and Asp residues playing an important role in catalytic activity. The search for low-cost pullulanase with distinct features, possibly from easily grown bacterium, is of interest for industrial applications. Earlier starch hydrolysis was carried out by traditional acid hydrolysis method. Since the 1960s, almost all processes to convert starch to glucose have changed to the enzymatic hydrolysis method. .
