Continuous asymmetric ketone reduction processes with recombinant Escherichia coli.
The reduction of methyl acetoacetate was carried out in continuously operated biotransformation processes catalyzed by recombinant Escherichia coli cells expressing an alcohol dehydrogenase from Lactobacillus brevis. Three different cell types were applied as biocatalysts in three different cofactor regeneration approaches. Both processes with enzyme-coupled cofactor regeneration catalyzed by formate dehydrogenase or glucose dehydrogenase are characterized by a rapid deactivation of the biocatalyst. By contrast the processes with substrate-coupled cofactor regeneration by alcohol dehydrogenase catalyzed oxidation of 2-propanol could be run over a period of 7 weeks with exceedingly high substrate and cosubstrate concentrations of up to 2.5 and 2.8 mol L(-1), respectively. Even under these extreme conditions, the applied biocatalyst showed a good stability with only marginal leakage of intracellular cofactors.
Schroer
Kirsten
K
Institut für Biotechnologie 2, Forschungszentrum Jülich, 52425 Jülich, Germany.
Mackfeld
Ursula
U
Tan
Ivy Ai Wei
IA
Wandrey
Christian
C
Heuser
Florian
F
Bringer-Meyer
Stephanie
S
Weckbecker
Andrea
A
Hummel
Werner
W
Daussmann
Thomas
T
Pfaller
Rupert
R
Liese
Andreas
A
Lütz
Stephan
S
D000090:Acetoacetates / Q000378:metabolism; D019149:Bioreactors; D001711:Biotransformation; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000378:metabolism*; D005560:Formate Dehydrogenases; D005948:Glucose Dehydrogenases; D007659:Ketones / Q000378:metabolism*