Industrial Biotransformations

-Lactamase
Pseudomonas solanacearum
O
NH
1) Reaction conditions
[1]: 0.92 M, 100 g · L –1 [109.13 g · mol –1 ]
pH: 7.0
T: 25 °C
medium: aqueous
reaction type: carboxylic acid amide hydrolysis
catalyst: suspended whole cells
enzyme: β-lactamhydrolase (β-lactamase)
strain: Pseudomonas solanacearum
CAS (enzyme): [9001–74–5]
2) Remarks
1 (-)-1
● The cells are grown by fermentation and the resulting cell mass is frozen and stored.
● The frozen cell mass is added in its crude form to the aqueous reaction solution. The advantage
is that the biotransformation can be performed at different sites.
● The reaction rate is increased by some cell lysis, which is caused by the freeze-thaw process,
liberating the enzyme.
● The whole cells are used since the isolated microbial enzyme is only of limited stability.
● Control of pH is not required, since the product 2-amino-cyclopent-2-ene carboxylic acid acts
as its own buffer.
● The lactam is extracted with dichloromethane.
● The amino acid can be recovered from the aqueous phase as the hydrochloride by acidification
(HCl) and evaporation of the water.
3) Flow scheme
Not published.
E
O
NH
H2N COOH
(+)-2
EC 3.5.2.6
1 = 2-azabicylo[2.2.1]hept-5-en-3-one (γ-lactam)
2 = 4-amino-cyclopent-2-enecarboxylic acid Celltech Group plc
Fig. 3.5.2.6 – 1
422
+