Schroer Kirsten, Mackfeld Ursula, Tan Ivy Ai Wei, Wandrey Christian, Heuser Florian, Bringer-Meyer Stephanie, Weckbecker Andrea, Hummel Werner, Daussmann Thomas, Pfaller Rupert, Liese Andreas, Lütz Stephan
Institut für Biotechnologie 2, Forschungszentrum Jülich, 52425 Jülich, Germany.
J Biotechnol. 2007 Dec 1;132(4):438-44. doi: 10.1016/j.jbiotec.2007.08.003. Epub 2007 Aug 7.
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.
