Amylase is an enzyme that is present in many shapes. It can be divided in three categories; alpha-, beta- and gamma-amylase. All three types are glucoside hydrolases and take part in the process of starch degradation by acting on α-1,4-glycosidic bonds to create short-chain sugars.
Amylase is used in for instance;
- Brewing and fermentation;
- Textile industry for designing textiles;
- Detergents in the laundry industry;
- Paper industry for sizing;
- Food industry for removal of starch, preparation of syrups etc.
α-amylase is an enzyme found in various forms in the nature. Two isoforms are found in the human body; salivary alpha amylase and pancreatitic alpha amylase. Both variants take part in the digestion of starch. α-amylase is also present in fungi, bacteria and different plants. As an example, α-amylase is produced during germination of seeds.
Unlike other amylases, α-amylase can hydrolyse alpha-bonds in starch at random locations on the polymer chain, thereby making it a faster enzyme compared to other amylases. The end products are maltos and glucose from amylopectin and maltos and maltotriose from amylose.
β-amylase is an enzyme found in fungi, bacteria and plants but not in humans. Unlike α-amylase, β-amylase can only degrade starch from the non-reducing end of the polymer chain by hydrolysis of the second α-1,4 glycosidic bond. The end product is thus maltose, i.e. two glucose units. As α-amylase, β-amylase is present in seeds and is used in a variety of applications, for instance malting. A high volume application is the production of high maltose syrups.
γ-amylase is an enzyme that is less frequently used in the industry. It degrades starch from the non-reducing end by hydrolysing the last α(1-4)glycosidic linkage, thereby yielding one glucose unit. In addition, it hydrolyse α(1-6) glycosidic linkages. The enzyme has a lower ph optimum compared to other amylases.