The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform

Zeev Rosenzweig - One of the best experts on this subject based on the ideXlab platform.

  • Glucose Oxidase–magnetite nanoparticle bioconjugate for Glucose sensing
    Analytical and Bioanalytical Chemistry, 2004
    Co-Authors: Liane M Rossi, Ashley D. Quach, Zeev Rosenzweig
    Abstract:

    Immobilization of bioactive molecules on the surface of magnetic nanoparticles is of great interest, because the magnetic properties of these bioconjugates promise to greatly improve the delivery and recovery of biomolecules in biomedical applications. Here we present the preparation and functionalization of magnetite (Fe_3O_4) nanoparticles 20 nm in diameter and the successful covalent conjugation of the enzyme Glucose Oxidase to the amino-modified nanoparticle surface. Functionalization of the magnetic nanoparticle surface with amino groups greatly increased the amount and activity of the immobilized enzyme compared with immobilization procedures involving physical adsorption. The enzymatic activity of the Glucose Oxidase-coated magnetic nanoparticles was investigated by monitoring oxygen consumption during the enzymatic oxidation of Glucose using a ruthenium phenanthroline fluorescent complex for oxygen sensing. The Glucose Oxidase-coated magnetite nanoparticles could function as nanometric Glucose sensors in Glucose solutions of concentrations up to 20 mmol L^−1. Immobilization of Glucose Oxidase on the nanoparticles also increased the stability of the enzyme. When stored at 4°C the nanoparticle suspensions maintained their bioactivity for up to 3 months.

  • Glucose Oxidase magnetite nanoparticle bioconjugate for Glucose sensing
    Analytical and Bioanalytical Chemistry, 2004
    Co-Authors: Liane M Rossi, Ashley D. Quach, Zeev Rosenzweig
    Abstract:

    Immobilization of bioactive molecules on the surface of magnetic nanoparticles is of great interest, because the magnetic properties of these bioconjugates promise to greatly improve the delivery and recovery of biomolecules in biomedical applications. Here we present the preparation and functionalization of magnetite (Fe3O4) nanoparticles 20 nm in diameter and the successful covalent conjugation of the enzyme Glucose Oxidase to the amino-modified nanoparticle surface. Functionalization of the magnetic nanoparticle surface with amino groups greatly increased the amount and activity of the immobilized enzyme compared with immobilization procedures involving physical adsorption. The enzymatic activity of the Glucose Oxidase-coated magnetic nanoparticles was investigated by monitoring oxygen consumption during the enzymatic oxidation of Glucose using a ruthenium phenanthroline fluorescent complex for oxygen sensing. The Glucose Oxidase-coated magnetite nanoparticles could function as nanometric Glucose sensors in Glucose solutions of concentrations up to 20 mmol L−1. Immobilization of Glucose Oxidase on the nanoparticles also increased the stability of the enzyme. When stored at 4°C the nanoparticle suspensions maintained their bioactivity for up to 3 months.

Liane M Rossi - One of the best experts on this subject based on the ideXlab platform.

  • Glucose Oxidase–magnetite nanoparticle bioconjugate for Glucose sensing
    Analytical and Bioanalytical Chemistry, 2004
    Co-Authors: Liane M Rossi, Ashley D. Quach, Zeev Rosenzweig
    Abstract:

    Immobilization of bioactive molecules on the surface of magnetic nanoparticles is of great interest, because the magnetic properties of these bioconjugates promise to greatly improve the delivery and recovery of biomolecules in biomedical applications. Here we present the preparation and functionalization of magnetite (Fe_3O_4) nanoparticles 20 nm in diameter and the successful covalent conjugation of the enzyme Glucose Oxidase to the amino-modified nanoparticle surface. Functionalization of the magnetic nanoparticle surface with amino groups greatly increased the amount and activity of the immobilized enzyme compared with immobilization procedures involving physical adsorption. The enzymatic activity of the Glucose Oxidase-coated magnetic nanoparticles was investigated by monitoring oxygen consumption during the enzymatic oxidation of Glucose using a ruthenium phenanthroline fluorescent complex for oxygen sensing. The Glucose Oxidase-coated magnetite nanoparticles could function as nanometric Glucose sensors in Glucose solutions of concentrations up to 20 mmol L^−1. Immobilization of Glucose Oxidase on the nanoparticles also increased the stability of the enzyme. When stored at 4°C the nanoparticle suspensions maintained their bioactivity for up to 3 months.

  • Glucose Oxidase magnetite nanoparticle bioconjugate for Glucose sensing
    Analytical and Bioanalytical Chemistry, 2004
    Co-Authors: Liane M Rossi, Ashley D. Quach, Zeev Rosenzweig
    Abstract:

    Immobilization of bioactive molecules on the surface of magnetic nanoparticles is of great interest, because the magnetic properties of these bioconjugates promise to greatly improve the delivery and recovery of biomolecules in biomedical applications. Here we present the preparation and functionalization of magnetite (Fe3O4) nanoparticles 20 nm in diameter and the successful covalent conjugation of the enzyme Glucose Oxidase to the amino-modified nanoparticle surface. Functionalization of the magnetic nanoparticle surface with amino groups greatly increased the amount and activity of the immobilized enzyme compared with immobilization procedures involving physical adsorption. The enzymatic activity of the Glucose Oxidase-coated magnetic nanoparticles was investigated by monitoring oxygen consumption during the enzymatic oxidation of Glucose using a ruthenium phenanthroline fluorescent complex for oxygen sensing. The Glucose Oxidase-coated magnetite nanoparticles could function as nanometric Glucose sensors in Glucose solutions of concentrations up to 20 mmol L−1. Immobilization of Glucose Oxidase on the nanoparticles also increased the stability of the enzyme. When stored at 4°C the nanoparticle suspensions maintained their bioactivity for up to 3 months.

Ashley D. Quach - One of the best experts on this subject based on the ideXlab platform.

  • Glucose Oxidase–magnetite nanoparticle bioconjugate for Glucose sensing
    Analytical and Bioanalytical Chemistry, 2004
    Co-Authors: Liane M Rossi, Ashley D. Quach, Zeev Rosenzweig
    Abstract:

    Immobilization of bioactive molecules on the surface of magnetic nanoparticles is of great interest, because the magnetic properties of these bioconjugates promise to greatly improve the delivery and recovery of biomolecules in biomedical applications. Here we present the preparation and functionalization of magnetite (Fe_3O_4) nanoparticles 20 nm in diameter and the successful covalent conjugation of the enzyme Glucose Oxidase to the amino-modified nanoparticle surface. Functionalization of the magnetic nanoparticle surface with amino groups greatly increased the amount and activity of the immobilized enzyme compared with immobilization procedures involving physical adsorption. The enzymatic activity of the Glucose Oxidase-coated magnetic nanoparticles was investigated by monitoring oxygen consumption during the enzymatic oxidation of Glucose using a ruthenium phenanthroline fluorescent complex for oxygen sensing. The Glucose Oxidase-coated magnetite nanoparticles could function as nanometric Glucose sensors in Glucose solutions of concentrations up to 20 mmol L^−1. Immobilization of Glucose Oxidase on the nanoparticles also increased the stability of the enzyme. When stored at 4°C the nanoparticle suspensions maintained their bioactivity for up to 3 months.

  • Glucose Oxidase magnetite nanoparticle bioconjugate for Glucose sensing
    Analytical and Bioanalytical Chemistry, 2004
    Co-Authors: Liane M Rossi, Ashley D. Quach, Zeev Rosenzweig
    Abstract:

    Immobilization of bioactive molecules on the surface of magnetic nanoparticles is of great interest, because the magnetic properties of these bioconjugates promise to greatly improve the delivery and recovery of biomolecules in biomedical applications. Here we present the preparation and functionalization of magnetite (Fe3O4) nanoparticles 20 nm in diameter and the successful covalent conjugation of the enzyme Glucose Oxidase to the amino-modified nanoparticle surface. Functionalization of the magnetic nanoparticle surface with amino groups greatly increased the amount and activity of the immobilized enzyme compared with immobilization procedures involving physical adsorption. The enzymatic activity of the Glucose Oxidase-coated magnetic nanoparticles was investigated by monitoring oxygen consumption during the enzymatic oxidation of Glucose using a ruthenium phenanthroline fluorescent complex for oxygen sensing. The Glucose Oxidase-coated magnetite nanoparticles could function as nanometric Glucose sensors in Glucose solutions of concentrations up to 20 mmol L−1. Immobilization of Glucose Oxidase on the nanoparticles also increased the stability of the enzyme. When stored at 4°C the nanoparticle suspensions maintained their bioactivity for up to 3 months.

D. R. Fravel - One of the best experts on this subject based on the ideXlab platform.

  • Localization of Glucose Oxidase with immunocytochemistry in the biocontrol fungus Talaromyces flavus
    Phytopathology, 1998
    Co-Authors: S. K. Stosz, S. Roy, C. Murphy, W. Wergin, D. R. Fravel
    Abstract:

    ABSTRACT Production of the enzyme Glucose Oxidase has been shown to be involved in the biological control of Verticillium wilt by Talaromyces flavus. In this study, the location of Glucose Oxidase was determined in T. flavus by immunocytochemistry using Glucose Oxidase-specific polyclonal antibody. Immunostaining revealed that Glucose Oxidase was both intracellular and extracellular. Old, as well as young, hyphal cells contained Glucose Oxidase, but labeling of the cell wall-associated enzyme decreased as the cells aged. Exocytosis rather than cell lysis was the primary means of release of Glucose Oxidase from cells. Enzyme stability studies confirmed that the Glucose Oxidase of T. flavus is an extremely stable enzyme, retaining 13% of its original activity after 2 weeks at 25°C and retaining activity for several days at temperatures up to 50°C.

Laxmi Ananthanarayan - One of the best experts on this subject based on the ideXlab platform.

  • Glucose Oxidase--an overview.
    Biotechnology advances, 2009
    Co-Authors: Sandip B. Bankar, Mahesh V. Bule, Rekha S. Singhal, Laxmi Ananthanarayan
    Abstract:

    Glucose Oxidase (beta-D-Glucose:oxygen 1-oxidoreductase; EC 1.1.2.3.4) catalyzes the oxidation of beta-D-Glucose to gluconic acid, by utilizing molecular oxygen as an electron acceptor with simultaneous production of hydrogen peroxide. Microbial Glucose Oxidase is currently receiving much attention due to its wide applications in chemical, pharmaceutical, food, beverage, clinical chemistry, biotechnology and other industries. Novel applications of Glucose Oxidase in biosensors have increased the demand in recent years. Present review discusses the production, recovery, characterization, immobilization and applications of Glucose Oxidase. Production of Glucose Oxidase by fermentation is detailed, along with recombinant methods. Various purification techniques for higher recovery of Glucose Oxidase are described here. Issues of enzyme kinetics, stability studies and characterization are addressed. Immobilized preparations of Glucose Oxidase are also discussed. Applications of Glucose Oxidase in various industries and as analytical enzymes are having an increasing impact on bioprocessing.

  • Optimization of Aspergillus niger Fermentation for the Production of Glucose Oxidase
    Food and Bioprocess Technology, 2008
    Co-Authors: Sandip B. Bankar, Mahesh V. Bule, Rekha S. Singhal, Laxmi Ananthanarayan
    Abstract:

    A number of nutritional factors influencing Glucose Oxidase (EC 1.1.3.4) production by Aspergillus niger NCIM 545 were studied. The synthesis of Glucose Oxidase by A. niger was investigated in two steps using submerged fermentation at 30 ± 2 °C and 180 rpm for 96 h. Primarily, nutritional components were selected by one-factor-at-a-time method, and the significance of each component with respect to Glucose Oxidase production was identified by Plackett–Burman design (seven variables including six nutritional viz. sucrose, sodium nitrate, peptone, calcium carbonate, magnesium sulfate, and potassium dihydrogen phosphate, and one dummy or unassigned variable were studied with eight experiments). In the second step, concentration of most significant factors and their interaction were studied with response surface methodology (central composite design). Each variable in the design was studied at five different levels, with all variables taken at a central coded value of zero. Considerable amount of Glucose Oxidase was produced from A. niger species with sucrose as the carbon source, sodium nitrate as the inorganic nitrogen source, and peptone as the organic nitrogen source. Glucose Oxidase activity increased remarkably by 28.93 fold (from 0.00993 to 0.29 U ml^−1) with CaCO_3-supplemented media. The outcome of Plackett–Burman design showed CaCO_3, peptone, and MgSO_4 as significant parameters. Further optimization using a three-factor central composite design with 20 experiments increased yield of Glucose Oxidase from 0.29 to 2.05 U ml^−1 (sevenfold) with a decrease in cultivation time from 96 to 72 h.