Dissertation / PhD Thesis/Book

PreJuSER-29118

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Verfahrensentwicklung zur Darstellung von (2R,5R)-Hexandiol mit Lactosbacillus kefir DSM20587

Haberland, J. (Corresponding author)FZJ*

2003
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/120

Report No.: Juel-4059

Abstract: The reduction of (2,5)-hexanedion to (2R,5R)-hexanediol with resting whole cells of Lactobacillus kefir DSM20587 was investigated as model reaction with a industrial background. The enantiopure diol is used for the synthesis of the chiral ligand DuPhos, which is used in homogeneous hydrogenation reactions. At first the kinetics and the stoichiometry of the reaction was investigated. Within the investigations of the stoichiometry of the reaction all extracellular metabolites were identified and quantified. In fed-batch experiments (2R,5R)-hexanediol was produced enantiopure with a purity of 93%. To obtain a synthesis to produce kg quantities a continuous stirred tank reactor (CSTR) with cell retention was established and characterized. The CSTR was run in 2-L scale and to look forward to a commercially used process kg quantities of (2R,5R)-hexanediol were produced during the practical work of this thesis. A space-time yield of 64 g*L$^{-1}$ d$^{-1}$ was achieved. The CSTR was completed by a coupled online liquid-liquid-extraction. As solvent for the extraction ethyl acetate was used. The extraction efficiency was >90%. The product was collected at the bottom of the distillation column. The ethyl acetate wa removed batchwise to crystallize the product. Besides the liquid-liquid-extraction other methods for downstream processing were tested. The results of the synthesis of (2R,5R)-hexanediol were transferred to another product and another biocatalyst. In an additional continuous experiment 2-octanone was stereospecifically reduced to (2R)-octanol. A space-time-yield of 42,4 g*L$^{-1}$ d$^{-1}$ was achieved for this reaction. With the use of baker's yeast and the same continuous setup 3-oxobutyric acid ethylester was reduced to (3S)-hydroxybutyric acid ethylester under aerobic conditions. For this reduction an enantiomeric excess of >95% and a space-time-yield of 15 g*L$^{-1}$ d$^{-1}$ was acieved.

Note: Record converted from VDB: 12.11.2012
Note: Bonn, Univ., Diss., 2003

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Contributing Institute(s):

1. Biotechnologie 2 (IBT-2)

Research Program(s):

1. Biotechnologie (L02)

Appears in the scientific report 2003

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Database coverage:

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