Kinetic model for oligosaccharide hydrolysis using suspended and immobilized enzymes

A novel kinetic model that describes the hydrolysis of oligosaccharide usin g the suspended enzyme has been constructed by introducing the selectivity of the enzyme for cleaving each alpha-1,6 glycosidic bond of the substrate. The Michaelis-Menten type kinetic constants, K-m and V-max, and the select ivity coefficient, alpha, are estimated by fitting the model with the exper imental data obtained under various conditions. The new constant, alpha, is estimated at 0.411, and almost the same as the experimental values. The mo del has been extended for the immobilized enzyme system by taking into acco unt the intraparticle mass transfer resistance. The model constants are est imated similarly to the case of the suspended enzyme system, alpha(imm) (al pha for the immobilized enzyme system) is a little higher than that in the suspended enzyme system. K-m(imm) and V-max(imm), are much greater than tho se for the suspended enzyme system. The estimated values of the effective d iffusivities in the support particle an a few order of magnitude smaller th an those in aqueous solution. The model well simulates both experimental re sults obtained in the suspended and immobilized enzyme systems. (C) 1998 El sevier Science S.A. All rights reserved.