CONCLUSIONS
GAXA spheres can be prepared by Ca” coupling of the
polysaccharides and GA cross-linking of the gelatin
ingredient present in the initial gel solution. It appears
that GAXA spheres can be used successfully in urease
encapsulation for several reasons. Encapsulated urease
exhibits higher enzymatic activity through pH and
temperature variations when compared to its free form.
GAXA spheres also retain 75% of maximum urease
activity after 20 reuses in 40 d without any surface
deformation. By changing the xanthan content of the
initial polymer mixture, the water uptake of the
spheres can he changed. Furthermore, GAXA spheres