Journal article
Reaction and strain engineering for improved stereo-selective whole-cell reduction of a bicyclic diketone
Bioenergy and Biomass, Biosystems Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark1
Biosystems Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark2
Risø National Laboratory for Sustainable Energy, Technical University of Denmark3
Reduction of bicyclo[2.2.2]octane-2,6-dione to (1R, 4S, 6S)-6-hydroxy-bicyclo[2.2.2]octane-2-one by whole cells of Saccharomyces cerevisiae was improved using an engineered recombinant strain and process design. The substrate inhibition followed a Han-Levenspiel model showing an effective concentration window between 12 and 22 g/l, in which the activity was kept above 95%.
Yeast growth stage, substrate concentration and a stable pH were shown to be important parameters for effective conversion. The over-expression of the reductase gene YDR368w significantly improved diastereoselectivity compared to previously reported results. Using strain TMB4110 expressing YDR368w in batch reduction with pH control, complete conversion of 40 g/l (290 mM) substrate was achieved with 97% diastereomeric excess (de) and >99 enantiomeric excess (ee), allowing isolation of the optically pure ketoalcohol in 84% yield.
Language: | English |
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Publisher: | Springer Berlin Heidelberg |
Year: | 2008 |
Pages: | 1111-1118 |
ISSN: | 14320614 and 01757598 |
Types: | Journal article |
DOI: | 10.1007/s00253-007-1240-1 |
6-hydroxybicyclo(2.2.2)octane-2-one Bioreduction Biotechnology Bridged Bicyclo Compounds Chemistry Diastereoselectivity Dicarbonyl Hydrogen-Ion Concentration Microbial Genetics and Genomics Microbiology Oxidation-Reduction Process optimisation Reductase Saccharomyces cerevisiae Saccharomyces cerevisiae Proteins Stereoisomerism Substrate Specificity Substrate inhibition Toxicity Whole-cell Yeast bicyclo(2.2.2)octane-2,6-dione