A simple method for the rapid and economical immobilization of glucose isomerase

The immobilization of glucose isomerase by adsorption on a macroreticular polystyrene sulphonate cation exchanger equilibrated with Ti⁴⁺, Zr⁴⁺, V⁵⁺ ions, followed by alkaline glutaraldehyde-induced crosslinking, is described. Experimental conditions are fixed for a selective and optimal retention of glucose isomerase and for its minimal leaching during subsequent use as a continuous compact glucose isomerase bed reactor, the performance of which is assessed on a laboratory scale for glucose isomerization. Factors influencing the glucose isomerase activity on solid supports, such as ratios of enzyme load - carrier - metal ion concentration, substrate feed concentration, residence period, loss of enzymic activity during storage and use, etc. are studied. The merits and drawbacks of the newly developed glucose isomerase reactor are discussed.