Industrial Biotransformations

Aspartase
Escherichia coli
1 = fumaric acid
2 = aspartic acid
Fig. 4.3.1.1 – 1
1) Reaction conditions
[1]: 1.5 M, 174.1 g · L –1 [116.07 g · mol –1 ]
[2]: 1.5 M, 199.5 g · L –1 [133.10 g · mol –1 ]
pH: 8.5
T: inlet 27 °C; outlet 37 °C
medium: aqueous
reaction type: C-N-bond cleavage
catalyst: immobilized enzyme
enzyme: l-aspartate-ammonia lyase (fumaric aminase, aspartase)
strain: Escherichia coli
CAS (enzyme): [9027–30–9]
2) Remarks
HOOC
COOH
● The presence of 1 mM MgCl 2 enhances the activity and stability of the enzyme.
E
+ NH 3
HOOC
1 L-2
COOH
EC 4.3.1.1
BioCatalytics Inc.
● By using isolated, on silica-based support immobilized enzyme, a higher productivity was
achieved than the comparable process using immobilized cells.
● Tanabe Seiyaku uses for the same synthesis an immobilized whole cell system since 1973 (see
page 500), in contrast to Mitsubishi Petrochemical Co. Ltd., which uses suspended whole cells
(see page 498). Kyowa Hakko Kogyo Co, Ltd., Japan, also uses an immobilized enzyme (see
page 496).
● The product solution is acidified to pH 2.8, chilled and the precipitated product is filtered off.
494
NH2