Effect of High Product Concentration in a Dual Fed-batch Asymmetric 3-oxo Ester Reduction by Baker's Yeast
| Autor: | Ifoeng Chin-Joe, Jack T. Pronk, Adrie J. J. Straathof, Jaap A. Jongejan, Joseph J. Heijnen |
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| Rok vydání: | 2002 |
| Předmět: | |
| Zdroj: | Biocatalysis and Biotransformation. 20:337-345 |
| ISSN: | 1029-2446 1024-2422 |
| Popis: | Baker's-yeast-mediated asymmetric ethyl 3-oxobutanoate reduction using a fed-batch feeding strategy for both the 3-oxo ester and the electron donor, was explored as potential production system for enantiopure ethyl ( S )-3-hydroxybutanoate. The dual feed strategy was based on kinetic and stoichiometric data. One major aspect is the effect of high product concentrations on the progress of the reduction. According to initial rate experiments, product inhibition occurs at concentrations above 600 mM product causing a 10-fold decrease of the initial biomass-specific reduction rate. By using optimized feed rates and a biomass concentration of 43 g dw l m 1, a product concentration of 350 mM was reached within 80 h with a degree of conversion of 95%. The volumetric productivity was 0.58 g l m 1 h m 1, using 2.1 kg pressed yeast kg product m 1 and 0.52 kg glucose kg product m 1. During the fed-batch biotransformation the reduction rate continuously decreased and reduction ceased after 80 h, d... |
| Databáze: | OpenAIRE |
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