Whole-cell biocatalysis in ionic liquids with recombinant Escherichia coli

Stefan Bräutigam, doctoral thesis Technische Universität München, 2008

The use of recombinant whole cell biocatalysts expressing suitable enzymes in combination with a biphasic process design with ionic liquids as second solvent proved to be an efficient method for the production of fine chemicals. Therefore, 21 ionic liquids have been studied for the asymmetric reduction of 6 prochiral ketones with 4 different recombinant Escherichia coli strains. Reaction engineering analyses of these systems demonstrated the production of pure chiral alcohols with high space-time yields of up to 150 g/l/d. Mathematical analysis showed that mainly mass transport across the cell membrane is rate limiting.


  • Bräutigam S, Bringer-Meyer S, Weuster-Botz D (2007): Asymmetric whole cell biotransformations in biphasic ionic liquid/water-systems by use of recombinant Escherichia coli with intracellular cofactor regeneration. Tetrahedron: Asymmetry 18: 1883-1887.
  • Bräutigam S, Dennewald D, Schürmann M, Lutje-Spelberg J, Pitner W-R, Weuster-Botz D (2009): Whole cell biocatalysis: Evaluation of new hydrophobic ionic liquids for efficient asymmetric reduction of prochiral ketones. Enz Microbial Technol 45: 310-316.