title: Immobilization of horseradish peroxidase onto kaolin.
abstract: Kaolin showed as a very perspective carrier for the enzyme immobilization and it was used for the adsorption of horseradish peroxidase (HRP). The effects of the enzyme concentration and pH on the immobilization efficiency were studied in the reaction with pyrogallol and anthraquinone dye C.I. Acid Violet 109 (AV 109). In addition, Fourier transform infrared spectroscopy, scanning electron microscopy and analysis by Brunauer-Emmett-Teller were performed for kaolin, thermally activated kaolin and the immobilized enzyme. It has been shown that 0.1 IU of HRP-kaolin decolorized 87 % of dye solution, under the optimal conditions (pH 5.0, temperature 24 °C, dye concentration 40 mg/L and 0.2 mM of H2O2) within 40 min. The immobilized HRP decolorization follows the Ping Pong Bi-Bi mechanism with dead-end inhibition by the dye. The biocatalyst retained 35 ± 0.9 % of the initial activity after seven cycles of reuse in the decolorization reaction of AV 109 under optimal conditions in a batch reactor. The obtained kinetic parameters and reusability study confirmed improvement in performances of k-HRP compared to free, indicating that k-HRP has a great potential for environmental purposes.
authors.affiliation: Faculty of Technology and Metallurgy, Innovation Center, University of Belgrade, Karnegijeva 4, 11000, Belgrade, Republic of Serbia.
authors.forename: Nataša Ž
authors.initials: NŽ
authors.lastname: Šekuljica
authors.affiliation: Faculty of Technology and Metallurgy, Innovation Center, University of Belgrade, Karnegijeva 4, 11000, Belgrade, Republic of Serbia.
authors.forename: Nevena Ž
authors.initials: NŽ
authors.lastname: Prlainović
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000, Belgrade, Republic of Serbia.
authors.forename: Jelena R
authors.initials: JR
authors.lastname: Jovanović
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000, Belgrade, Republic of Serbia.
authors.forename: Andrea B
authors.initials: AB
authors.lastname: Stefanović
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000, Belgrade, Republic of Serbia.
authors.forename: Veljko R
authors.initials: VR
authors.lastname: Djokić
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000, Belgrade, Republic of Serbia.
authors.forename: Dušan Ž
authors.initials: DŽ
authors.lastname: Mijin
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000, Belgrade, Republic of Serbia. zknez@tmf.bg.ac.rs.
authors.forename: Zorica D
authors.initials: ZD
authors.lastname: Knežević-Jugović
mesh_terms: D031215:Armoracia / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry; D007616:Kaolin / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D010940:Plant Proteins; D007616:Kaolin; D006735:Horseradish Peroxidase
keywords: Adsorption; Horseradish peroxidase; Kaolin; Kinetic parameters; Wastewater treatment