title: Immobilization of glucose isomerase.
abstract: The immobilization of glucose isomerase (D-xylose ketol isomerase, EC 5.3.1.5) by covalently bonding to various carriers and by adsorption to ion exchange resins was attempted in order to obtain a stable immobilized enzyme which can be used for continuous isomerization of glucose in a column. Of the covalent bonding methods, the colloidal silica-glutaraldehyde method showed the highest binding capacity and gave the most stable immobilized glucose isomerase. The Ludox HS-30 bound glucose isomerase column showed a half-life of 24 days and an enzyme usage of 0.07 units per gram of isomerized sugar (d.s, fructose 45%). Of the resins used, the macromolecular type or porous type strongly basic anion exchange resins showed the highest binding capacity and gave the most stable immobilized glucose isomerase. The Amberlite IRA-904 resine-bound glucose isomerase showed a half-life of 23 days and an enzyme usage of 0.06 units per gram of isomerized sugar (d.s., fructose 45%). Based on the ease of the immobilization process, the possibility of carrier reuse and the extensive use already achieved by ion exchange resins in the sugar industry, IRA-904 resin was selected as the candidate for commercialization.
mesh_terms: D000327:Adsorption; D019747:Aldose-Ketose Isomerases; D000837:Anion Exchange Resins; D002238:Carbohydrate Epimerases / Q000378:metabolism; D003102:Colloids; D004800:Enzymes, Immobilized / Q000378:metabolism; D005976:Glutaral; D006207:Half-Life; D012116:Resins, Plant; D012822:Silicon Dioxide
chemical_list: D000837:Anion Exchange Resins; D003102:Colloids; D004800:Enzymes, Immobilized; D012116:Resins, Plant; D012822:Silicon Dioxide; C028629:IRA-93 resin; D002238:Carbohydrate Epimerases; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase; D005976:Glutaral