Industrial Biotransformations

Amidase
Klebsiella terrigena
2
H
N
N
H
1) Reaction conditions
[1]: 0.15 M, 20 g · L –1 [129.16 g · mol –1 ]
pH: 8.0
T: 40 – 47 °C
medium: aqueous
reaction type: carboxylic acid amide hydrolysis (kinetic resolution)
catalyst: suspended whole cells
enzyme: acylamide amidohydrolase (amidase)
strain: Klebsiella terrigena DSM 9174
CAS (enzyme): [9012–56-0]
2) Remarks
O
(R/S)-1
NH 2
E
+ H2O
H
N
N
H
(S)-2
EC 3.5.1.4
● Primary screening was done starting from soil samples using growth media that contained racemic
carboxamides. The cell-free media of the individual clones were then analysed on TLC
plates, only strains with approximately 50 % of the racemic carboxamides were chosen.
● This kinetic resolution is attractive because the starting material can be easily prepared:
● The microorganism can be grown in fermenters on the racemic carboxamides at the same
time as the biotransformations are taking place.
O
OH
+
H
N
N
H
(R)-1
O
NH2
+ NH 3
1 = piperazine-2-carboxamide
2 = piperazine-2-carboxylic acid Lonza AG
Fig. 3.5.1.4 – 1
Fig. 3.5.1.4 – 2
N
N
1 = pyrazine-2-carboxamide
2 = piperazine-2-carboxamide
O
NH 2
10 % Pd/C
85 % EtOH
20 bar H2
H
N
N
H
1 (R/S)-2
O
NH2
379