Enzyme Reaction Engineering

To investigate the impact of kinetics on reactor design, we have to (i) develop the pertinent kinetic rate equation (ii) insert this rate law into the equation for the reactor we intend to operate and (iii) integrate over all degrees of conversion. 

Biocatalysis. Andreas S. Bommarius and Bettina R. Riebel Copyright 2004 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 3-527-30344-8 

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Figure 5.1 Approach to kinetic modeling of enzyme reactions linkage of different elements of enzyme reaction engineering (top) parameter estimation and determination of operating points (bottom) (Bommarius, 1993).

Figure 7-3. Steps of process optimization in enzyme reaction engineering.

Kinetic parameters are defined in Sect. 7-4. Two examples will illustrate the implications of complex reactions in enzyme reaction engineering. 

With respect to benzaldehyde, (R)-oxynitrilase exhibits saturation kinetics (Michaelis Menten kinetics, see Sect. 7.4.2.1) and a maximum reaction rate is reached above a concentration of about 5 mmol L 1. The chemical reaction presents a linear increase of the reaction rate with increasing benzaldehyde concentration, representing first order kinetics, when the concentration of HCN is kept constant (see Fig. 7-13). As a consequence the enzymatic reaction becomes more dominating at lower concentrations of the substrate benzaldehyde (for HCN as substrate the same kinetic behavior occurs, data not shown). Accordingly an enzyme reactor would be suitable that works under minimum average substrate concentrations. These requirements are satisfied by the continuous stirred tank reactor (CSTR). In Sect. 7.5.2.1 this aspect of enzyme reaction engineering will be discussed further. 

Other properties that have to be considered in enzyme reaction engineering are pH effects on the reaction... 

The methods of enzyme reaction engineering have already shown their benefits in numerous industrial processes which are being established successfully. Hopefully it can be concluded from this article that process development for the application of enzymes in organic synthesis can be performed on a rational basis. 

Vasic-Racki, D., Findrik, Z., and VrsalovicPresecki, A. (2011) Modeling as a tool of enzyme reaction engineering for enzyme reactor development. Appl. Microbiol. Biotechnol, 91, 845-856. 

RM Blanco, G Alvaro, JM Guis. Enzyme reaction engineering design of peptide synthesis by stabilized trypsin. Enzyme Microb Technol 13 573-583, 1991. 

R Femandez-Lafuente, CM Rosell, JM Guisan. Enzyme reaction engineering synthesis of antibiotics catalysed by stabilized penicillin G acylase in the presence of organic solvents. Enzyme Microb Technol 13 898-905, 1991. 

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