Processed gellan gum beads as covalent immobilization carriers

Abstract

Abstract With the aim of employing gellan gum (GG) beads as covalent immobilization carriers, these beads were subjected to two different activation processes. These activation processes differed from one another with respect to the employed polyamine compound as either polyethyleneimine (PEI) or chitosan (CS) was employed. The polyamine treatment step was optimized with the central composite design, and it was shown that the recommended settings for the PEI concentration and the PEI solution pH were 6.15% (w/v) and 8.30, respectively. On the other hand, the optimum CS solution was shown to be a 2.20% (w/v) solution with a pH value of 2.77. The PEI processed GG beads caused the immobilized β- D -galactosidase (β-gal) to exhibit a more acidic pH optimum than that offered when the CS processed beads were employed. Nevertheless, the two immobilized β-gal samples offered similar temperature profiles. They also exhibited comparable operational stabilities where 81.22 ± 2.63% and 85.17 ± 1.78% of their initial activities were preserved throughout the 14th reusability run of the PEI and the CS processed GG beads, respectively.