Cereal Chem 53:270 - 281. | VIEW
A Kinetic Comparison of Streptomyces Glucose Isomerase in Free Solution and Adsorbed on DEAE-Cellulose.
N. E. Lloyd and K. Khaleeluddin. Copyright 1976 by the American Association of Cereal Chemists, Inc.
Mycelium from a Streptomyces sp. was treated with a dilute solution of a cationic surfactant to prepare an extract containing glucose isomerase (D-xylose ketol isomerase, EC 184.108.40.206). The isomerase was partially purified and immobilized by adsorption on DEAE-cellulose. Recovery of activity in the immobilized form was complete. The velocities of glucose-fructose interconversions were examined using the integrated form of the Michaelis-Menten equation for reversible reactions. Both free and immobilized forms of the enzyme gave the same maximum velocities and Michaelis constants in batch reactions. The immobilized form gave reaction velocities in shallow-packed bed reactors which were slightly lower than in stirred-batch reactors. The lower velocity was attributed principally to channeling. The equilibrium fructose content of reaction mixtures varied from 46.5% at 30 C to 52.4% at 70 C.