amylases

Amylases are enzymes that catalyze the hydrolysis of starch and related polysaccharides into sugars. They form a broad class of carbohydrate-degrading enzymes found in plants, animals, and microorganisms and play a central role in digestion as well as in many industrial processes. In humans, pancreatic and salivary amylases begin breaking down dietary starch in the mouth and small intestine, producing maltose, maltotriose, and dextrins.

Amylases are commonly classified into three main types by mode of action and substrate preferences. Alpha-amylase is endo-acting and cleaves internal alpha-1,4-glycosidic bonds in starch to produce maltose, maltotriose, and limit dextrins. Beta-amylase is exo-acting and releases maltose from nonreducing ends of starch. Gamma-amylase, also known as glucoamylase, is an exo-glucosidase that hydrolyzes both alpha-1,4 and alpha-1,6 bonds to yield glucose. Each type has characteristic optimum pH ranges and is assigned EC numbers: alpha-amylase (EC 3.2.1.1), beta-amylase (EC 3.2.1.2), and glucosamylase/gamma-amylase (EC 3.2.1.3).

Natural sources and production: In humans, amylases are produced by salivary glands and the pancreas. Plants use amylases in seeds and fruits to mobilize stored starch. Industrial production relies on microorganisms such as Bacillus and Aspergillus species, and on engineered strains that yield thermostable variants for high-temperature processes.

Applications and significance: Amylases are widely used in the food and beverage industry to convert starch into fermentable sugars for baking, brewing, and ethanol production. They also find use in detergents, textile processing, and paper production. In medicine, serum amylase measurements aid in diagnosing pancreatic or salivary gland disorders and assessing enzyme function.