Enzymes
The commercial enzymes for liquefaction (Liquozyme Supra,
alpha-amylase) and for saccharification (Suhong GA II, glucosidase)
were purchased from Novozymes. The amount of enzyme that can
hydrolyze 5.26 g soluble starch per hour at pH 5.6 and 37 C is
defined as 1 KNU (Kilo Novo alpha-amylase Unit). The amount of
enzyme that cleaves 1 mmol of maltose per min at pH 4.3 and 25 C
is defined as 1 AGU (Amyloglucosidase Novo Unit) (Novo, 1981).
Liquozyme Supra is a heat-stable a-amylase (EC 3.2.1.1) from
Bacillus licheniformis with a declared activity of 90 KNU/g. Suhong
GA II is a glucoamylase (EC 3.2.1.1) from Aspergillus niger with
a declared activity of 500 AGU/g.