Biphasic whole-cell synthesis of R-2-octanol with recycling of the ionic liquid

Danielle Dennewald, doctoral thesis Technische Universität München, 2011

Whole-cell biocatalysis in biphasic systems permits the synthesis of inhibiting chiral alcohols if appropriate non-water miscible ionic liquids are used. Taking the asymmetric reduction of 2-octanone to R-2-octanol by a recombinant Escherichia coli as a model reaction, a detailed characterisation of the biocatalytic reaction was performed with [HMPL][NTF] as ionic liquid. This made the asymmetric synthesis of R-2-octanol in a simple batch at a conversion > 99 % and at an enantiomeric excess > 99.5 % possible. The recyclability of the ionic liquid over a large number of cycles including the biotransformation, the separation of the ionic liquid, the product isolation, as well as the solvent’s subsequent reuse is of large importance for industrial applications. It could be demonstrated for the first time that the ionic liquid was recyclable over at least 25 process cycles without any consequences on the batch biotransformation.


  • Dennewald D, Weuster-Botz D (2012): Ionic liquids and whole-cell catalyzed processes. In Dominguez de Maria P (ed): Ionic liquids in biotransformations and organocatalysis: Solvents and beyond, John Wiley & Sons, Inc. Hoboken, New Jersey: 261-314.
  • Dennewald D, Hortsch R, Weuster-Botz D (2012): Evaluation of parallel millilitre-scale stirred-tank bioreactors for the study of biphasic whole-cell biocatalysis with ionic liquids. J Biotechnol 157: 253-257.
  • Dennewald D, Pitner WR, Weuster-Botz D (2011): Recycling of the ionic liquid phase in process integrated biphasic whole-cell biocatalysis. Proc Biochem 46: 1132-1137.
  • 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.