Improving the catalytic behavior of inulin fructotransferase under high hydrostatic pressure.

BACKGROUND The demand for difructose anhydride III ( DFA III), a novel functional sweetener, is growing continuously. It is produced from inulin by inulin fructotransferase ( IFTase). In this study, high hydrostatic pressure ( HHP), as a clean technology, was first applied to further improve the catalytic efficiency of IFTase in the process. RESULTS The maximum activity of IFTase was obtained under 200 MPa at 60 °C. Meanwhile, HHP lowered the energy barrier necessary for the enzymatic reaction and decreased the volume between the reactants and the transition state. Under this condition, the optimal pH for the enzymatic reaction shifted from 5.5 to 6.0. The activity was further enhanced by 65.2% in the presence of 1.5 mol L⁻¹ NaCl. CONCLUSION The catalytic reaction of IFTase was performed under HHP for the first time. HHP, as a promising green technology for bioconversion, significantly accelerated the enzymatic reaction under the appropriate operational conditions. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]