Cross-linked glucose isomerase

The invention relates to a novel water-insoluble glu­cose isomerase which is formed by a crystalline enzyme converted to solid form by cross-linking. The inven­tion also concerns a process for the preparation of the novel crystalline glucose isomerase by cross-link­ing with dialdehyde in the presence of a compound con­taining at least one amino group, and the use of this novel enzyme preparation as an isomerization catalyst.