Effect of temperature, pH and storage time on the stability of an extracellular fructosyltransferase from Aspergillus oryzae IPT-301

Efeito da temperatura, pH e tempo de armazenamento na estabilidade de frutosiltransferase extracelular de Aspergillus oryzae IPT-301

Abstract

In this work, it was determined the influence of temperature, pH and storage time on the enzymatic activity and stability of an extracellular fructosyltransferase (FTase E.C.2.4.1.9) from Aspergillus oryzae IPT-301 produced by submerged fermentation. The thermodynamic parameters showed a tendency for increasing enzyme denaturation with the rise in temperature. The maximum transfructosylation activity was obtained at the incubation pH 5.5. During storage at 4 °C, the transfructosylation activity decreased, whereas the hydrolytic activity increased, especially in the first nine hours, a time in which the enzyme presented 45.6% of its initial transfructosylation activity. These results contributed to the improvement of the conditions of storage, immobilization and use of the soluble fructosyltransferases (FTase) in fructooligosaccharide (FOS) production.

Keywords:
Submerged fermentation; Soluble enzyme; Enzyme stability; Thermodynamic parameters; Aspergillus; Transfructosylation activity