Theoretical Treatment of Packed-Bed Enzyme Reactors

Packed-bed enzyme reactors, those employing enzymes immobilized onto a particulate phase that is subsequently packed into a column, may be characterized by their column capacity, C, and the degree of reaction P. The parameter C is defined in Eq. 4.23, 

An equation equivalent to the Michaelis-Menten equation has been derived for immobilized enzymes in packed-bed reactor systems, and is given in Eq. 4.24  

Equation 4.24 has been experimentally tested using a carboxymethylcellulose stationary phase onto which the enzyme ficin (E.C.3.4.22.3) has been immobilized. Ficin catalyzes the hydrolysis of a variety of ester substrates, but the substrate N-benzoyl-L-arginine ethyl ester (BAEE) has been chosen for this series of experiments (Eq. 4.25)  

For packed-bed enzyme reactors, these results show that low flow rates ensure quantitative conversion of substrate into detectable products. The variation of K m with flow rate indicates that lower flow rates produce higher K m values, so that the linear region of the saturation kinetic curve extends to higher substrate concentrations at lower flow rates. This effect becomes significant when complete conversion does not occur during the residence time of the analyte. 

A more recent study involving glucose oxidase immobilized by physical entrapment in hydroxyethyl methacrylate-based hydrogels has shown that Eq. 4.24 can 

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