Immobilization of glucose isomerase in surface-modified alginate gel beads

Hasırcı, Nesrin
In this study, glucose isomerase enzyme was entrapped into modified and nonmodified calcium alginate gel beads. Various characteristics of free and immobilized enzymes such as the optimum pH, temperature and dependence of activity on storage and operational stability were evaluated. The optimum pH and temperature of free and immobilized glucose isomerase were found to be the same values as 7.5 and 60C, respectively. For free and immobilized enzymes, kinetic parameters were calculated as 1.79 x 10(-2) and 8.27 x 10(-3) mol/L for Km, and 2.39 x 10(-3) and 6.03 x 10(-3) mol/L min for V-max, respectively. After 42 days of storage at 4C, free enzyme retained 56% of its initial activity, while for the immobilized enzyme, this value was observed as 86%. The immobilized samples were used repeatedly 22 times by retaining more than 85% of their initial activity.


Immobilization of invertase in conducting polymer matrices
Selampinar, F; Akbulut, Ural; Ozden, MY; Toppare, Levent Kamil (1997-09-01)
This paper reports a novel approach in the electrode immobilization of an enzyme, invertase, by electrochemical polymerization of pyrrole in the presence of enzyme. The polypyrrole/invertase and polyamide/polypyrrole/invertase electrodes were constructed by the entrapment of enzyme in conducting matrices during electrochemical polymerization of pyrrole. This study involves the preparation and characterization of polypyrrole/invertase and polyamide/polypyrrole/invertase electrodes under conditions compatible...
Poly(hydroxybutyrate-co-hydroxyvalerate) nanocapsules as enzyme carriers for cancer therapy: an in vitro study
Baran, ET; Ozer, N; Hasırcı, Vasıf Nejat (2002-05-01)
In the present paper, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nanocapsules were prepared by a double emulsion-solvent evaporation procedure (w/o/w) for the encapsulation of model enzymes (L-asparaginase, catalase, glucose oxidase) and bovine serum albumin. To increase the encapsulation efficiency and activity of the encapsulated enzyme, numerous modifications were made in the compositions of the phases of double emulsion. For the preparation of low molecular weight PHBV, the polymer was treated with so...
Immobilization of invertase and glucose oxidase in conducting H-type polysiloxane/polypyrrole block copolymers
Gursel, A; Alkan, S; Toppare, Levent Kamil; Yagci, Y (Elsevier BV, 2003-01-01)
In this study, immobilizations of enzymes, invertase and glucose oxidase, were achieved in conducting copolymers of N-pyrrolyl terminated polydimethylsiloxane/polypyrrole (PDMS/PPy) matrices via electrochemical polymerization. The kinetic parameters, v(max) (maximum reaction rate) and K-m (substrate affinity), of both free and immobilized enzymes were determined. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate, on enzyme activity and film morphologies was examined. ...
Immobilization of glucose oxidase onto gelatin for biosensor construction
Emregul, E; Sungur, S; Akbulut, Ural (Informa UK Limited, 2005-01-01)
The properties of a glucose biosensor made by immobilization of glucose oxidase onto gelatin in a layer of electrochemically deposited polyaniline have been investigated. Glucose oxidase was immobilized within gelatin cross-links with chromium(III) acetate. The glucose oxidase biosensor was developed by forming a polyaniline-deposited electrode surface as support for the immobilized enzyme gel, in order to increase its durability. The polyaniline/gelatin/glucose oxidase biosensor has been characterized usin...
ARICA, MY; Hasırcı, Vasıf Nejat (1993-01-01)
Glucose oxidase was immobilized onto poly(2-hydroxyethyl methacrylate) (pHEMA) membranes by two methods: by covalent bonding through epichlorohydrin and by entrapment between pHEMA membranes. The highest immobilization efficiency was found to be 17.4% and 93.7% for the covalent bonding and entrapment, respectively. The K(m) values were 5.9 mmol dm-3, 8.8 mmol dm-3 and 12.4 mmol dm-3 for free, bound and entrapped enzyme, respectively. The V(max) values were 0.071 mmol dm-3 min-1, 0.067 mmol dm-3 min-1 and 0....
Citation Formats
H. TÜMTÜRK, G. DEMİREL, H. ALTINOK, S. AKSOY, and N. Hasırcı, “Immobilization of glucose isomerase in surface-modified alginate gel beads,” JOURNAL OF FOOD BIOCHEMISTRY, pp. 234–246, 2008, Accessed: 00, 2020. [Online]. Available: