Immobilized invertase studies on glass–ceramic support from coal fly ashes

Invertase was covalently immobilized on new coal fly ashes glass-ceramic support with zinc sulfate (GCSZn). The coupling process of proteins was demonstrated by X-ray diffraction (XRD). There was no change in the optimum pH (4.6) but optimum temperature increased from 55 °C for free invertase to 60 °C for immobilized derivative. The activation energy decreased after immobilization (37.31 ± 3.40 kJ/mol) in spite of free invertase (51.34 ± 5.21 kJ/mol). There was an improvement in the Michaelis–Menten constant for sucrose hydrolysis after immobilization being 15 times lower compared to that for free invertase (0.30 ± 0.01 mmol). After ten reuses at 25 ± 2 °C, the immobilized invertase lost only 9% of initial activity, but at the optimum temperature (60 °C), the activity decrease was about 70%, what it is economically feasible under energetic view point for industrial application.

► The new support from coal fly ashes added with ZnSO4 to immobilize invertase. ► The support is important such as resistance mechanical and microbiological. ► The sucrose hydrolysis must not be in the optimum temperature. ► An economical protocol was established to prepare derivative for invert sugar. ► The support can be a viable alternative to reduce environmental pollution.