Hydrolysis of cellobiose by immobilized (beta)-glucosidase entrapped in maintenance-free gel spheres.

摘要

A crude preparation of Aspergillus niger (beta)-glucosidase(27.5 cellobiase units mg(sup (minus)1)protein at 40(degree)C, pH 5.0) was immobilized on concanavalin A-Sepharose (CAS). The cellobiase activity of the immobilized enzyme was 1334 units mg(sup (minus)1) dried CAS or 108 units mL(sup (minus)1) of CAS gel. The (beta)-glucosidase-CAS complex was entrapped within cross-linked propylene glycol alginate/bone gelatin gel spheres that possessed between 0.67 and 2.35 cellobiase units mL(sup (minus)1) spheres depending on their size. The effect of cellobiase concentration (10 to 300 m(und M)) on the activity of native, immobilized, and gel-entrapped enzyme was determined and found that concentrations of cellobiase between 10 and 180 m(und M) cellobiase were not inhibitory to the entrapped enzyme, unlike that found to occur with the native and immobilized enzyme. Exogenous ion addition was not necessary to maintain the structural integrity of the spheres which were stable for 4 days at 40(degrees)C. 9 refs., 3 figs.