Non-separating effects in a centrifugal partition chromatographic reactor for the enzymatic production of L-amino acids

The selective enzymatic hydrolysis of the L-enantiomer of a racemic mixture of N-acetyl-methionine to produce chiral amino acids was studied. The integration of the enzymatic hydrolysis reaction in a liquid-liquid centrifugal partition chromatographic reactor enables improved conversion of the substrate. The influence of the composition of the phase system on mass transfer, partition behaviour and reaction kinetics was identified by independent experiments. These relations are incorporated in a predictive model for the effluent profiles of the chromatographic reactor. This method enables optimisation of the reactor performance by fine tuning of the phase system and enzyme concentration. Aqueous two-phase systems were applied in centrifugal partition chromatography and phase stability determines possible phase compositions. Enzyme concentration in the stationary phase determines the productivity of the process. Damkohlers number I (Dal) should exceed 0.14 for the studied hydrolysis reaction. Improved conversion for the hydrolysis reaction in CPC was found to be caused by dilution of the substrate due to mass transfer limitation, rather than by the chromatographic reactor concept. The model predictions and the experimental reaction chromatograms agreed within experimental error. (C) 1999 Elsevier Science Ltd. All rights reserved.