Abstract

ENCAPSULATION OF INVERTASE IN BARIUM ALGINATE BEADS

Michele Vitolo*

Abstract

Invertase (E.C. 3.2.1.26) was encapsulated in barium alginate beads. The gelation was carried out at 30oC by stirring (360 rpm and 540 rpm) using alginate concentrations (5 g/L and 10 g/L), barium nitrate concentrations (0.1M and 0.2M), and three pH of alginate-invertase solution (4.0, 6.7 and 8.0). Invertase encapsulation yielded 75.2% and encapsulated invertase activity yielded 0.249 U/mL. These results were obtained using beads produced with 10 g/L alginate (SG800) and 0.1M barium nitrate at pH 4.0, 30oC and 540 rpm. The kinetic constants for soluble and encapsulated invertase, calculated using Hanes-Woolf’s plot, were KM = 52.9 mM, Vmax = 0.368 U/mL, (KM)encap = 7.51 mM and (Vmax)encap = 0.269 U/mL. The beads were reused three times batchwise without significant loss of invertase activity.

Keywords: Immobilization, invertase, alginate, encapsulation, entrapment.