Immobilization of high temperature-resistant GH3 β-glucosidase on a magnetic particle Fe3O4-SiO2-NH2-Cellu-ZIF8/zeolitic imidazolate framework

The magnetic particle Fe 3 O 4 -SiO 2 -NH 2 -Cellu-ZIF8 (FSNCZ8) was used to immobilize the high-temperature resistant GH3 β-glucosidase (Tpebgl3) from the Thermomotoga petrophila DSM 13995. The Tpebgl3 has great potential in the catalytic conversion of pharmaceutically active components. The magnetic carrier (FSNCZ8) which provided stronger adsorption capacity, magnetic and high-temperature stability than the previously discussed Fe 3 O 4 -NH 2 -Cellu-ZIF8 without tetraethyl silicate coated. The properties of FSNCZ8-Tpebgl3 (FSNCZ8-T) were as follows: The optimal temperature and pH were 90 °C and 5.5, respectively; the highest activity of FSNCZ8-T approached 2672 U/g; Fe 2+ enabled immobilized enzyme to increase its relative activity to 194%. The main characteristics of FSNCZ8-T, including thermal stability, pH stability, and glucose tolerance, were greatly enhanced by adding Fe 2+ , which was also superior to free enzymes; moreover, the residual activity of FSNCZ8-T was 74% of the initial activity at the end of 10 repeated cycles.