Industrial Biotransformations

Monooxygenases / Aryl alcohol dehydrogenase / Benzaldehyde dehydrogenase
Pseudomonas putida ATCC 33015
1 = 2-methylquinoxaline
2 = 2-hydroxy-methylquinoxaline
3 = 2-quinoxalinecarbaldehyde
4 = 2-quinoxalinecarboxylic acid
1) Reaction conditions
[1]: [144.17 g · mol –1 ]
[2]: benzyl alcohol < 1.5 g · L –1 [160.17 g · mol –1 ]
pH: 7.0–7.5
T: 29–30 °C
medium: mineral salt medium
reaction type: oxidation
catalyst: whole cell
enzyme: monooxygenase
enzyme: benzyl alcohol dehydrogenase, aryl alcohol dehydrogenase
enzyme: benzaldehyde dehydrogenase, benzaldehyde:NAD + oxidoreductase
strain: Pseudomonas putida ATCC 33015
CAS (enzyme): [144378-37-0] / [37250-26-3] / [37250-93-4]
2) Remarks
N
N
E1
1 2
E2 N
Fig. 1.14.13.62 / 1.1.1.90 / 1.2.1.28 – 1
3
N
CHO
EC 1.14.13.62 /
1.1.1.90 / 1.2.1.28
Pfizer Inc.
● P. putida can catalyze the bioconversion of 2-methylquinoxaline using benzyl alcohol as the
inducer and sole carbon source.
● The bioconversion is sensitive to the accumulation of substrate concentrations above 1.5 g · L –1
and benzyl alcohol concentration above 1 g · L –1 .
● Carefully controlled additions of substrate and benzyl alcohol are very important for achieving
a successful bioconversion.
● It appears that compounds with two nitrogens, such as quinoxaline and piperazine, are better
substrates for P. putida than quinoline derivatives.
● Chemical synthesis from the di-N-oxide is deemed unsuitable for scale-up due to the mutagenic
and thermal properties of the reactant.
● The P. putida process yields a product concentration greater than 10 g · L –1 and is therefore
more likely to be commercially feasible.
N
N
OH
E3 N
4
N
COOH
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