Enzymes can be classified into 6 main classes according to the type of reaction they catalyze: oxidoreductases (peroxidase, laccase, tyrosinase, glucose oxidase), transferases (phosphorylase, glycosyltransferase, acyltransferase), hydrolases (cellulase, amylase, xylanase, lipase, protease), lyases (decarboxylase, aldolase, dehydratase), isomerases (racemase, epimerase, isomerase), and ligases (ligase, synthase, acyl CoA synthase). Among them the three classes, oxidoreductases, transferases, and hydrolases, are the most abundant types of Hydrolases occupy more than 50% of the total biocatalysts market followed by oxidoreductases and transferases. The major application of these three enzymes is shown in Table .