The typical pretreatment method for enzymatic hydrolysis of
starches to fermentable sugars is based on a two-step method. In
the first step starch is liquefied by heat-stable a-amylase (EC 3.2.1.1) in order to decrease the viscosity of gelatinized starch solution and to produce short-chained dextrins, by breaking down the a-1,4-glycosidic bonds in the middle of amylose and amylopectinchains. During the second step of starch hydrolysis (saccharification) the dextrins are saccharified by glucoamylase (amyloglucosidase, EC 3.2.1.3) to obtain monomeric sugars (glucose)