TEMPERATURE-DEPENDENCE OF STABILITY AND ACTIVITY OF AN IMMOBILIZED GLUCOSE ISOMERASE IN A PACKED-BED

A mathematical model describing the kinetics of the conversion of glucose to fructose by an immobilized glucose isomerase has been developed. The model is a straight‐forward one and based on known kinetic behaviour of glucose isomerase and on limitations posed by diffusional resistance when a spherical particle containing the enzyme is considered. The model has been used to derive a relationship between initial enzyme activity and temperature. It can be demonstrated that the relationship between activity and temperature shows deviations from the familiar Arrhenius plot. The same holds for the activity half life time in a packed bed column. Experimental material confirming the theoretical considerations is presented. The experimental results have been applied to estimate some important parameters of the material used. An Arrhenius‐type relationship is shown to hold for the estimated enzyme activity as well as for the kinetics of the deactivation process. The parameters obtained can be used in temperature optimization studies for the packed bed conversion process. The influences of initial activity, particle size and temperature on the production of fructose are discussed. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim