Testing of the Effect of Reaction Parameters on the Enzyme Immobilization by Adsorption and Cross-Linking Processes with Kinetic Desorption Method

Dániel Radva, János Spanyol and Judit Kosáry*

Department of Applied Chemistry, Faculty of Food Science, Corvinus University of Budapest, Villányi út 29, HU-1118 Budapest, Hungary

Article history:
Received July 17,2009
Accepted April 4, 2010

Key words:
enzyme immobilization, adsorption and cross-linking, β-glucosidase, Amberlite IRA-900, kinetic desorption method

Summary:
The activity of enzymes after the immobilization by weak interactions such as adsorption or adsorption followed by a cross-linking reaction can change easily not only during further application but during the activity measured via desorption and/or inactivation of enzymes. The changes in activity could be a consequence of the interactions between the enzyme and support. In this work a quick and efficient method is developed that permits studying of the strength and properties of the forces between the enzymes and support by examining the kinetics of desorption and/or inactivation. Applying this new cyclic kinetic desorption method, the effect of reaction parameters on immobilization could also be studied. The efficiency of this method was tested for optimizing the parameters for immobilization of β-glucosidase on Amberlite IRA 900 anion exchange resin by an adsorption followed by a cross-linking with glutaraldehyde to form potential preparation for food industry. The following parameters were chosen: concentration (0.10 M) of the buffer (sodium acetate, pH=5.5) and the ratio of carrier to enzyme (10:1) for the adsorption step, then the time of treatment (1 min) and concentration (0.25, by mass per volume) of glutaraldehyde for the cross-linking by using the kinetic desorption method. The activity of this preparation was 57 mmol/(min·g) in respect of dry resin. It was established that the effect of different parameters on this enzyme immobilization could be characterized by the new cyclic kinetic desorption method in a quick and efficient way; furthermore, it permitted separate testing of the effect of parameters on the adsorption and cross-linking processes.

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