Fructooligosaccharides (FOS) are sucrose derivatives containing fructosyl units. Obtaining FOS via enzymatic route with enzymes of microbial origin called fructosyltransferases (FTase, E.C.184.108.40.206), has been studied using strains of the fungus Aspergillus oryzae to obtain the mycelial extract. The present proposal aims the immobilization of mycelial extract previously crosslinked with glutaraldehyde by entrapment in calcium or barium alginate beads. Beads production conditions, like formulations, effect of crosslinking cations concentration in alginate, diameter, aspect of the beads and stability at storage were evaluated. The immobilization condition that produces the highest FOS yields used alginate (4.0 % w/w) crosslinked with 0.2 mol.L-1 calcium chloride and the smallest diameter beads. These optima conditions generated spherical beads, with homogeneous, porous and continuous surfaces, with larger resistance to mechanical compression and higher storage time stability at 4 °C. The bulk of these expressive gains evidences the potential of the application of Aspergillus oryzae IPT-301 mycelial FTase in FOS production after crosslinking the mycelium with glutaraldehyde and its involvement in calcium alginate beads.