Saccharification during the beer fermentation process is usually
carried out by starch hydrolyzing enzymes from malt such
as ˛-amylase, ˇ-amylase and limitdextrinase. There are also some
other different types of enzymes produced from malt at the
former stage of the beer fermentation process such as protein
hydrolyzing enzymes i.e. endopeptidase and carboxypeptidase and
cell wall hydrolyzing enzymes i.e. endo ˇ-1,4-glucanase, endo ˇ-1,3-
glucanase and ˇ-glucan solubilase [20,21]. The starch hydrolyzing
enzymes in WBFB might be reused for hydrolyzing the starch
residue in WBFB at the former stage of ethanol production if
the activity of these enzymes was not totally lost during thermal
treatment during beer production. Actually the activity of
starch hydrolyzing enzyme may be preserved as Stark and Tetrault
[27] pointed out some starch saccharifying enzymes isolated from
bacterial species which were able to perform the saccharification
process at higher temperature 60–90 ◦C.