Alpha-amylase is a kind of enzyme being able to hydrolyzes alpha bonds of large alpha-linked polysaccharides including starch and glycogen. It is a very small, stable enzyme which is resistant to many unfavorable conditions. It can hydrolyzes starch and glycogen to maltose and glucose, respectively so that providing energy for human beings and animals. Alpha-amylase is present in almost all kinds of plants, animals and microbes. It has many industrial applications. For example, it can be used in the production of ethanol through breaking starches in grains into fermentable sugars. It can also be used during the production of high-fructose corn syrup. In addition, it can be used in some dishwashing and starch-removing detergents.