Treated calcium pectinate beads for the covalent immobilization of β-d-galactosidase.
The calcium pectinate (CP) gel beads were treated with polyethyleneimine (PEI) and glutaraldehyde (GA). This treatment greatly enhanced the beads' mechanical strength. Moreover, it enabled the CP beads to covalently immobilize enzymes, such as β-d-galactosidase (β-gal). The central composite design (CCD) was applied to optimize the PEI/GA treatment while employing the observed activity of the immobilized β-gal as a response. The CCD predicted that treating the CP beads with a 3.49% PEI solution of pH 10.55, followed by a 5.66% GA solution in 0.1M phosphate buffer pH 7.02 would allow for the immobilization of 6.25U/g gel of the β-gal. The verification experiment run at these optimum conditions offered 6.285±0.22U/g gel immobilized β-gal which was in close agreement with the predicted value. The reusability study revealed that the β-gal immobilized onto the treated CP beads retained 79.34% of its initial activity after being used for fourteen times.
Department of Natural and Microbial Chemistry, National Research Center, El-Behooth St., Dokki, Cairo, Egypt; Centre of Scientific Excellence-Group of Encapsulation and Nanobiotechnology, Cairo, Egypt. Electronic address: drmarwawahba@yahoo.com.
Marwa I
MI
Wahba
D000468:Alkalies / Q000737:chemistry; D000704:Analysis of Variance; D001230:Aspergillus / Q000201:enzymology*; D055162:Biocatalysis / Q000187:drug effects; D004602:Elements; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005976:Glutaral / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D055595:Mechanical Phenomena; D008863:Microspheres; D010368:Pectins / Q000494:pharmacology*; D011094:Polyethyleneimine / Q000737:chemistry; D013696:Temperature; D001616:beta-Galactosidase / Q000378:metabolism*
D000468:Alkalies; D004602:Elements; D004800:Enzymes, Immobilized; D010368:Pectins; D011094:Polyethyleneimine; D001616:beta-Galactosidase; D005976:Glutaral
Central composite design; Covalent immobilization; Glutaraldehyde; Pectin; Polyethyleneimine; β-d-Galactosidase