2022-01-042022-01-042011-06-05Kök, S. vd. (2011). "Vinyl triazole carrying metal-chelated beads for the reversible immobilization of glucoamylase". Journal of Applied Polymer Science, 120(5), 2563-2570.0021-89951097-4628https://doi.org/10.1002/app.33325https://onlinelibrary.wiley.com/doi/full/10.1002/app.33325http://hdl.handle.net/11452/23834Poly(ethylene glycol dimethacrylate-1-vinyl-1,2,4-triazole) [poly(EGDMA-VTAZ)] beads with an average diameter of 100-200 μm were obtained by the copolymerization of ethylene glycol dimethacrylate (EGDMA) with 1-vinyl-1,2,4-triazole (VTAZ). The copolymer hydrogel bead composition was determined by elemental analysis and was found to contain 5 EGDMA monomer units for each VTAZ monomer unit. The poly(EGDMA-VTAZ) beads were characterized by swelling studies and scanning electron microscopy (SEM). The specific surface area of the poly(EGDMA-VTAZ) beads was found 65.8 m2/g. Cu 2+ ions were chelated on the poly(EGDMA-VTAZ) beads. The Cu 2+ loading was 82.6 μmol/g of support. Cu2+-chelated poly(EGDMA-VTAZ) beads with a swelling ratio of 84% were used in the immobilization of Aspergillus niger glucoamylase in a batch system. The maximum glucoamylase adsorption capacity of the poly(EGDMA-VTAZ)-Cu2+ beads was 104 mg/g at pH 6.5. The adsorption isotherm of the poly(EGDMA-VTAZ)-Cu 2+ beads fitted well with the Langmuir model. Adsorption kinetics data were tested with pseudo-first- and second-order models. The kinetic studies showed that the adsorption followed a pseudo-second-order reaction model. The Michaelis constant value for the immobilized glucoamylase (1.15 mg/mL) was higher than that for free glucoamylase (1.00 mg/mL). The maximum initial rate of the reaction values were 42.9 U/mg for the free enzyme and 33.3 U/mg for the immobilized enzyme. The optimum temperature for the immobilized preparation of poly(EGDMA-VTAZ)-Cu2+-glucoamylase was 65°C; this was 5°C higher than that of the free enzyme at 60°C. The glucoamylase adsorption capacity and adsorbed enzyme activity slightly decreased after 10 batch successive reactions; this demonstrated the usefulness of the enzyme-loaded beads in biocatalytic applications. The storage stability was found to increase with immobilization.eninfo:eu-repo/semantics/closedAccessPolymer scienceAdsorptionEenzymesMetal-polymer complexesAfiinity chromatographyCatalaseAdsorptionPurificationAdsorptionCatalystsChelationChemical analysisCopolymerizationCopolymersEnzyme activityEnzyme immobilizationEthyleneEthylene glycolMonomersNitrogen compoundsScanning electron microscopyAdsorbed enzymeAdsorption capacitiesAdsorption kineticsAspergillus nigerAverage diameterBatch systemsBiocatalytic applicationsCopolymer hydrogelsElemental analysisEthylene glycol dimethacrylateFree enzymeGlucoamylaseImmobilized enzymeInitial rateKinetic studyLangmuir modelsMetal-polymer complexesMichaelis constantsMonomer unitsOptimum temperatureReversible immobilizationSecond-order modelsSecond-order reactionSEMStorage stabilitySwelling ratioSwelling studiesEnzymesArticle0002883401000082-s2.0-79952483004256325701205Polymer scienceCibacron Blue F 3Ga; Cryogels; Muramidase