Evaluation of organic-inorganic hybrid nanoflower's enzymatic activity in the presence of different metal ions and organic solvents

Abstract

In the present study, lipase-inorganic hybrid nanoflowers (L-hNFs) have indicated to possess several novel characteristics that are significant in terms of industrial worth. In detail, we reported the production of lipase-inorganic hybrid nanoflowers in different parameters and evaluated synthesized nanoflowers' enzymatic activity in the presence of different concentrations of metal ions and organic solvents. The optimum pHs of free enzyme, L-hNFs (0.02, 0.05, and 0.1) and L-hNFs (0.03) were pH 8, 7 and 6, respectively. L-hNFs (0.05) displayed the highest enzymatic activity in high alkaline pH values (10, 11, and 12) compared to both free enzyme and other L-hNFs. While the free enzyme showed no activity at pH 12, L-hNFs (0.05) maintained 57% of their activity. The optimum temperatures of the free lipase and L-hNFs were 30 °C and 40 °C, respectively. Free lipase activity decreased with temperature while L-hNFs had higher enzyme activity at 40 °C and 50 °C. Even in the case of increasing incubation and organic solvent and metallic ion concentration in which free lipase cannot completely maintain its activity, L-hNFs were able to protect their activity. L-hNFs exhibited excellent thermal and pH stability and high resistance to metallic ions and organic solvents at various concentrations for 3 h, 6 h, and overnight. This new lipase-inorganic hybrid nanobiocatalyst may be promising in many industrial processes such as chemical, biochemical, pharmaceutical, and biotechnological ones.

Keywords: Enzymatic activities; Lipase-inorganic hybrid nanoflowers; Metal ions; Organic solvents.