Immobilization of Laccase Through Inorganic-Protein Hybrids Using Various Metal Ions

In this study, the inorganic-protein hybrid strategy was employed for immobilization of laccase from Rhus vernicifera (Rvlac) using various metals calcium, cobalt, copper, and zinc (Zn). The efficient synthesis of hybrids for Rvlac immobilization was noted at 4 °C for incubation of 24 h. Among these hybrids, the maximum encapsulation yields (EY) of 90.1% and relative activity (RA) of 225% to free enzyme were recorded for Zn and Rvlac based inorganic-protein hybrids as Zn₃(PO₄)₂-Rvlac. The upper optimum pH, and temperature values were observed of 4.0, and 45 °C after immobilization as compared to 3.5, and 40 °C for the free enzyme, respectively. After encapsulation, Rvlac showed a significant improvement up to 11.4-fold in pH and 5.7-fold in temperature the activity profiles. Free enzyme completely lost its activity at 60 °C after 2 h of incubation, whereas Zn₃(PO₄)₂-Rvlac retained its residual activity of 56.7% under similar conditions. After ten cycles of reusability, Zn₃(PO₄)₂-Rvlac possessed high residual activity of 90.8%. This study showed that the variation in the metal ions for immobilization of Rvlac as inorganic-protein hybrids significantly altered EY and RA. Also, Zn₃(PO₄)₂-Rvlac proved more efficient as compared to free laccase that can be beneficially employed for biotechnological applications.

The online version contains supplementary material available at 10.1007/s12088-022-01000-5.