The enzymatic isomerization of glacose to fructose is attracting significant attention f r o m scientific as well as industrial quarters. In recent years, high fructose syrups ("isosyrups") produced b y enzymatic isomerization of high DE-syrups have been introduced successfully, primarily i n the U.S.A.A decisive factor for the ability of isosyrups t o compete is enzyme costs. T h e development of immobilized glucose isomerase makes multiple use of the enzyme possible and thus makes the econom y of the isomerization process more attractive.Sweetzyme is the trade name of an immobilized glucose isomerase. i%e enzyme is presently being marketed for batchlre-use isomerization. A special quality suited for continuous column plug-flow isomerization is under development. T h e properties of the t w o qualities and conditions for use in batch and column isomerization processes are described.