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 solu-
tion and to produce short-chained dextrins, by breaking down the
a-1,4-glycosidic bonds in the middle of amylose and amylopectin
chains. During the second step of starch hydrolysis (saccharifica-
tion) the dextrins are saccharified by glucoamylase (amyloglucosi-
dase, EC 3.2.1.3) to obtain monomeric sugars (glucose)