Asymmetric syntheses with phototrophic microorganisms

Jan Havel, doctoral thesis Technische Universität München, 2006

Chiral alcohols are important intermediates for the production of optically active ingredients. Their biosynthesis can easily be achieved by stereoselective reduction of prochiral ketones. Phototrophic microorganisms have the essential enzymes for these reductions but they were so far not technically applied due to the necessity of light addition. The scope of this thesis was the investigation and characterisation of the potential of cyanobacteria for asymmetric synthesis. Especially halogenated ketones were found to be converted with high stereoselectivity to their corresponding chiral alcohols. Another important finding was the ability of these phototrophic microorganisms to perform asymmetric syntheses without the addition of light. This made the technical application of cyanobacteria feasible for asymmetric synthesis. The corresponding oxidoreductase was isolated and identified on the example of a selected cyanobacterium.


  • Hölsch K, Havel J, Haslbeck M, Weuster-Botz D (2008): Identification, cloning and characterization of a novel ketoreductase from the cyanobacterium Synechococcus sp. strain PCC 7942. Appl Environ Microbiol 74: 6697-6702.
  • Havel J, Franco-Lara E, Weuster-Botz D (2008): A parallel bubble column system for the cultivation of phototrophic microorganisms. Biotechnol Lett 30: 1197-1200.
  • Havel J, Weuster-Botz D (2007): Cofactor regeneration in phototrophic cyanobacteria applied for asymmetric reduction of ketones. Appl Microbiol Biotechnol 75: 1031-1037.
  • Franco-Lara E, Havel J, Peterat F, Weuster-Botz D (2006): Model-supported optimization of phototrophic growth in a stirred-tank photo-bioreactor. Biotechnol Bioeng 95: 1177-1187.
  • Havel J, Link H, Hofinger M, Franco-Lara E, Weuster-Botz D (2006): Comparison of genetic algorithms for experimental multi-objective optimization on the example of medium design for cyanobacteria. Biotechnol J 1: 549-555.
  • Havel J, Weuster-Botz D (2006): Comparative study of cyanobacteria as biocatalysts for the asymmetric synthesis of chiral building blocks. Eng Life Sci 6: 175-179.