Alginate Beads Encapsulation Matrix for Urease and Polyethyleneglycol-Urease

Abstract

Urease was immobilized activated PEG-5000 and encapsulated urease and PEG modified urease within alginate beads. Encapsulated urease and PEG-urease were thoroughly characterized for pH, temperature and stabilities and these properties were compared with free and PEG modified enzyme. A 34 and 57% mass and 19.3 and 43% activity yield of urease and PEG-urease resulted following encapsulation. The average diameter for the beads was found to be 2.5 mm for urease bead and 1.8 mm for PEG-urease bead. The stabilities of PEG-urease beads at pH 6.0 were higher than those of urease beads. PEG-urease beads retained 70% of initial activity after reusing seven times at pH 6.0. Also time dependency of substrate conversion was determined for enzyme beads.