Investigation of Optimal Conditions for Production, Characterization, and Immobilization of Fructosyltransferase and β-Fructofuranosidase by Filamentous Fungi

Abstract

This work's objective was the extracellular production, partial characterization, and immobilization of the enzymes fructosyltransferase (Ftase) and β-fructofuranosidadase (Ffase) by filamentous fungi. Aspergillus niger ATCC 9642 and Penicillium brasilianum were evaluated for the production of fructosyltransferase (Ftase) and β-fructofuranosidadase (FASE) enzymes. The A. niger presented the highest activity of FTase (24.86 µmol/min.mL) and FFase (28.68 µmol/min.mL) in medium composed of 20% sucrose, 0.5% yeast extract, 1% NaNO3, 0.05% MgSO4.7 H2O, 0.25% KH2PO4, 0.5% NH4Cl and 0.25% NaCl inoculated using 5x107spores/mL and incubated at 25°C, pH 5.5, 150 rpm for 48 h. Presenting optimum pH and temperature of 2.39 and 60°C. Thermal stability has shown that the enzyme FFase is more thermally stable when compared to FTase. Stability against different pHs showed similar behavior for FTase and FFase; the optimum pH being between 2.0 and 3.0. FTase and FFase showed storage stability in freezing and refrigeration temperature for approximately 400 h. The kinetic parameters, Km and Vmax, for the sucrose substrate were 24.60mM and 104.16 μmol/min.mL for FTase and 3.91mM and 20.24 μmol/min.mL for FFase. The immobilization process displayed a yield of 6744.66% for FFase and 3928.90% for FTase, with enzymatic activities of 364.79 U/g and 220.34 U/g, and 4 and 3 times reuse, respectively.