Immobilization of glucose isomerase-containing Streptomyces phaeochromogenus cells to chitosan-formaldehyde gel.

Abstract

The immobilization of glucose isomerase-containing Streptomyces phaeochromogenus cells on various gel supports was investigated. The highest activity was obtained by entrapment of cells at first step into chitosan-formaldehyde gel and cross-linked by glutaraldehyde. The yield of glucose isomerase activity of the S. phaeochromogenus cells immobilized on chitosan-formaldehyde gel was 71%. Enzymatic properties of the immobilized S. phaeochromogenus cells were investigated and compared with those of the intact cells. The optimal pH and temperature for the immobilized cells were 8 and 80°C, respectively, similar to those for the intact cells. The immobilized glucose isomerase-containing S. phaeochromogenus cells showed a similar kinetic behavior to that of intact cells. The glucose isomerase activity of the immobilized S. phaeochromogenus cells packed in the column was retained without a remarkable drop in activity after being used over 40 days.