Resistance to antibiotics by pathogenic bacteria constitutes a health burden and nanoparticles (NPs) are being developed as alternative and multipurpose antimicrobial substances. Magnetite (FeO np), manganese ferrite (MnFeO np) and nickel ferrite (NiFeO np) NPs were synthesized and characterized using thermogravimetric analysis, transmission electron microscopy, Fourier transformed infra-red, and X-ray diffraction. The minimal inhibitory concentrations (MIC) ranged from 0.
View Article and Find Full Text PDFIn this study, cellulose acetate (CA)/polyvinylpyrrolidone (PVP) and CA/PVP/Mn nanofibers were produced by the electrospinning method, and these cellulose-derived membranes were used as carriers for arginase immobilization for the first time. The structural and morphological analysis of these cellulose-derived nanofibers were determined by attenuated total reflection-Fourier to transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). After the immobilization process, it was observed that the thermal properties of the cellulose-derived nanofibers especially improved.
View Article and Find Full Text PDFThis study was aimed at synthesizing polyethyleneimine-coated magnetic nanoparticles and evaluating their effect on pathogenic bacteria. Polyethyleneimine-coated magnetite (PEIMnF) and nickel ferrite (PEINF) nanoparticles were succesfully synthesized and their surface groups, morphology and chemical structures were characterized using ATR-FTIR (Attenuated Total Reflectance Fourrier Transformed Infra-Red) and SEM (Scanning Electron Microscopy). TGA (Thermogravimetric analysis) was used to analyse the thermal behaviour and stability of synthesized nanomaterials.
View Article and Find Full Text PDFElectrospun polyvinyl alcohol (PVA)/Chitosan nanofibers were successfully prepared and were used as carriers for the first time in urease immobilization. Also, urease immobilized electrospun PVA/Chitosan nanofibers were applied for the removal of urea from artificial blood serum by recycled reactor. The nanofibers were optimized and synthesized by electrospinning technique according to the operational parameters.
View Article and Find Full Text PDFPolyvinyl alcohol (PVA)/Zn electrospun nanofibers that were a kind of polymer/ionic metal composite was successfully embedded in the hybrid fibers for the first time in the literature, due to chemical interactions between PVA and Zn. Also, the nanofibers were used as carriers for the first time in enzyme immobilization. The nanofibers were optimized and synthesized by electrospinning technique according to the operational parameters like as PVA concentration (%), Zn concentration (%), voltage (kV), needle tip-collector distance (cm) and injection speed (ml/h).
View Article and Find Full Text PDFIn this study, lipase was successfully immobilized on polyvinyl alcohol/alginate and polyethylene oxide/alginate nanofibers that were prepared by electrospinning. Results showed that nanofibers (especially polyvinyl alcohol/alginate) enhanced the stability properties of lipase. When the free lipase lost its all activity after 40-60min at high temperatures, both lipase immobilized nanofibers kept almost 65-70% activity at the same time.
View Article and Find Full Text PDFWe reported natural polymer-conjugated magnetic featured urease systems for removal of urea effectively. The optimum temperature (20-60 °C), optimum pH (3.0-10.
View Article and Find Full Text PDFThe purpose of the present work is improving stability properties of porcine pancreatic lipase (triacylglycerol lipase, E.C.3.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
September 2014
The aim of the present study is to synthesize TiO2 beads for urease immobilization. Two different strategies were used to immobilize the urease on TiO2 beads. In the first method (A), urease enzyme was immobilized onto TiO2 beads by adsorption and then crosslinking.
View Article and Find Full Text PDFThe aim of this study was enhancing of stability properties of catalase enzyme by encapsulation in alginate/nanomagnetic beads. Amounts of carrier (10-100 mg) and enzyme concentrations (0.25-1.
View Article and Find Full Text PDFPrep Biochem Biotechnol
September 2014
Catalase is one of the major antioxidant enzymes that catalyzes the hydrolysis of H2O2. The aim of this study was to suggest a new method for the assay of catalase activity. For this purpose, an amperometric biosensor based on glucose oxidase for determination of catalase activity was developed.
View Article and Find Full Text PDFPrep Biochem Biotechnol
February 2014
The scope of this study is to achieve carrier-bound immobilization of catalase onto magnetic particles (Fe₃O₄ and Fe₂O₃NiO₂ · H₂O) to specify the optimum conditions of immobilization. Removal of H2O2 and the properties of immobilized sets were also investigated. To that end, adsorption and then cross-linking methods onto magnetic particles were performed.
View Article and Find Full Text PDFArtif Cells Blood Substit Immobil Biotechnol
July 2009
Of all the food additives for which the FDA has received adverse reaction reports, the ones that most closely resemble true allergens are sulfur-based preservatives. Sulfites are used primarily as antioxidants to prevent or reduce discoloration of light-colored fruits and vegetables, such as dried apples and potatoes, and to inhibit the growth of microorganisms in fermented foods such as wine. This work aims to prepare an electrochemical biosensor based on bay leaf tissue homogenate that contains polyphenol oxidase enzyme abundantly for sulfite detection in foods.
View Article and Find Full Text PDFArtif Cells Blood Substit Immobil Biotechnol
June 2009
Although enzymes are effective biocatalysts that are widely used in biosensors, a major drawback that hampers many of these biotechnological applications of enzymes is their limited stability. Applications that use very pure, high value proteins need to employ effective stabilization technology, primarily due to cost considerations and availability of the proteins used. For this purpose, interest in bio-imprinting techniques increases because it allows stability characteristics of enzymes to be improved.
View Article and Find Full Text PDFDespite the increasing number of applications of biosensors in many fields, the construction of a steady biosensor remains still challenging. The high stability of molecularly bio-imprinted enzymes for its substrate can make them ideal alternatives as recognition elements for sensors. Urease (urea aminohydrolase, EC 3.
View Article and Find Full Text PDFInterest in molecular imprinted polymer techniques has increased because they allows for the improvement of some stability characteristics of enzymes. The high stability of molecularly imprinted enzymes for a substrate can make them ideal alternatives as recognition elements for sensors. A bioimprinted mushroom tissue homogenate biosensor was constructed in a very simple way.
View Article and Find Full Text PDFIn this study, porcine pancreatic lipase (EC 3.1.1.
View Article and Find Full Text PDFThe feasibility of using bis(delta2-2-imidazolinyl)-5,5'-dioxime (H2L) for the selective extraction of iron(III) from aqueous solutions was investigated by employing an solvent-extraction technique. The extraction of iron(III) from an aqueous nitrate solution in the presence of metal ions, such as cobalt(II), copper(II) and nickel(II), was carried out using H2L in binary and multicomponent mixtures. Iron(III) extraction has been studied as a function of the pH, equilibrium time and extractant concentration.
View Article and Find Full Text PDFArtif Cells Blood Substit Immobil Biotechnol
November 2003
Phospholipase A2 (PLA2; EC 3.1.1.
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