The inulin hydrolysis by recombinant exo-inulinases: determination the optimum temperatures and activation energies

Abstract

The advantages of recombinant enzymes over native include the control in a production environment, product purity and also high yield. The paper presents the determination the optimum temperatures and the activation energies for various origin recombinant exo-inulinases, among others from Aspergillus niger, A. awamori, Kluyveromyces marxianus and K. cicerisporus. The parameters were estimated based on the literature of the activity curves versus temperature for hydrolysis of inulin. It was assumed that both the hydrolysis reaction process and the deactivation process of recombinant exo-inulinase were first-order reactions by the enzyme concentration. A mathematical model describing the effect of temperature on recombinant exo-inulinase activity was used. Based on the comparison analysis, values of the activation energies Ea were in the range from 32.01 ± 7.80 to 43.83 ± 4.87 kJ mol- 1, the deactivation energies Ed were in the range from 83.93 ± 4.82 to 352.44 ± 14.26 kJ mol- 1 and the optimum temperature Topt were obtained in the range from 318.91 ± 1.19 to 328.76 ± 0.25 K.