With cells of Streptomyces spp K-45 isolated from soil, the immobilization of glucose isomerase by a series of treatments ; heat, carefully manipulated drying, extrusion with a thickening agent, and glutaraldehyde-induced crosslinking, was presented. This was aimed to obtain a mechanically stable form of whole cell containing glucose isomerase. The resulted pellet form had a good mechanical strength, compared with a commercial product, and showed 26 % of the activity recovery. The specific activity was 48.1 units per g of the dry material.
The immobilized glucose isomerase generally showed properties similar to those of the soluble enzyme ; optimal pH at 7.5∼9.0, optimal temperature at 80∼85℃, activation energy of 10.9 ㎉/mole, and K_m for glucose of 10.9 M. The immobilized enzyme was very thermostable and pH stable.
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