Industrial Biotransformations

Acetolactate decarboxylase
Bacillus brevis
Fig. 4.1.1.5 – 2
● The yeast was harvested and reused for a total of five consecutive fermentations.
● The enzyme can be activated at low pH values by addition of glutaraldehyde (about 0.05 %)
which intermolecularly cross-links the active dimer, which otherwise dissociates under acidic
conditions.
3) Flow scheme
Not published.
4) Process parameters
residence time: > 6 d
company: Novo Nordisk, Denmark
5) Product application
● The process can be applied for beer fermentation procedures, in which diacetyl is produced as
a by-product and has to be eliminated.
6) Literature
1 = α-acetolactate
2 = acetoin
3 = diacetyl
O
HO
1
COOH
EC 4.1.1.5
● Pedersen, S., Lange, N.K., Nissen, A.M. (1995) Novel industrial enzyme applications, Ann. N.
Y. Acad. Sci. 750, 376–390
450
α-acetolactate
decarboxylase
fast reaction
spontaneous
oxidative decarboxylation
slow reaction
O
2
OH
O
3
O
yeast
alcohol dehydrogenase