Document Type: Research Paper
The laccase enzyme is the largest group of Oxidoreductase enzymes and is capable of oxidizing a wide range of organic substrates to water along with molecular oxygen resuscitation. ZnO nanoparticles are known for their specific properties such as chemical stability, high electrochemical coupling rates, and wide range of absorption of radiation as multifunctional compounds. In this study, ZnO porous nanoparticles were synthesized and then the laccase enzyme was stabilized from the source of vermicellum tramitis by surface absorption method on the surface of synthesized nanoparticles. In the following, kinetic parameters, temperature stability, reusability and sustainability of the stabilized enzyme were measured and compared with the free enzyme. Given the results obtained at all three temperatures (40, 50 and 60 °C), the stabilized enzyme shows more temperature stability than the free enzyme in desired time range. The kinetic parameters Vm and Km did not significantly change with respect to the free enzyme. Enzyme activity returned to zero after 10 cycles of use and recycling. While the free enzyme lost its activity after three weeks of maintenance in laboratory condition, the stabilized enzyme retained 30% of its initial activity. These results indicate that ZnO porous nanoparticles can be used as a suitable substrate for the stabilization of laccase enzyme by surface adsorption method, and improves the stability parameters of the enzyme without affecting the kinetic properties of the enzyme.