Yazar "Baysal, Zuebeyde" seçeneğine göre listele
Listeleniyor 1 - 5 / 5
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Antibody purification with protein A attached supermacroporous poly(hydroxyethyl methacrylate) cryogel(Elsevier, 2009) Alkan, Hueseyin; Bereli, Nilay; Baysal, Zuebeyde; Denizli, AdilImmunoglobulin G (IgG) Purification from human plasma with protein A attached supermacroporous poly(hydroxyethyl methacrylate) [PHEMA] cryogel has been studied. PHEMA cryogel was prepared by bulk polymerization which proceeds in aqueous solution of monomer frozen inside a plastic syringe (cryo-polymerization). After thawing, the PHEMA cryogel contains a Continuous matrix having interconnected pores of 10-200 mu m size. Protein was covalently attached onto the PHEMA cryogel via cyanogen bromide (CNBr) activation. The maximum IgG adsorption oil the PHEMA/protein A cryogel Was found to be 83.2 mg/g at pH 7.4 from aqueous Solutions. The non-specific IgG adsorption onto the PHEMA cryogel was about 0.38 mg/g. The macropore size of the cryogel makes it possible to process blood cells without blocking the Column. Higher adsorption capacity was observed from human plasma (Lip to 88.1 mg/g). Adsorbed IgG was eluted using 0.1 M glycine-HCl buffer (pH 3.5) with a purity of 85%. PHEMA-protein A cryogel was used for repetitive adsorption/desorption of IgG without noticeable loss in IgG adsorption capacity after 10 cycles. PHEMA-protein A cryogel showed several advantages Such as simpler preparation procedure, good selectivity for IgG Purification from human plasma and good stability throughout repeated adsorption-desorption cycles. (C) 2009 Elsevier B.V. All rights reserved.Öğe Equilibrium and thermodynamic studies on biosorption of Pb(II) onto Candida albicans biomass(Elsevier Science Bv, 2009) Baysal, Zuebeyde; Cinar, Ercan; Bulut, Yasemin; Alkan, Hueseyin; Dogru, MehmetBiosorption of Pb(II) ions from aqueous solutions was studied in a batch system by using Candida albicans. The optimum conditions of biosorption were determined by investigating the initial metal ion concentration, contact time, temperature, biosorbent dose and pH. The extent of metal ion removed increased with increasing contact time, initial metal ion concentration and temperature. Biosorption equilibrium time was observed in 30 min. The Freundlich and Langmuir adsorption models were used for the mathematical description of biosorption equilibrium and isotherm constants were also evaluated. The maximum biosorption capacity of Pb(II) on C. albicans was determined as 828.50 +/- 1.05, 831.26 +/- 1.30 and 833.33 +/- 1.12 mg g(-1), respectively, at different temperatures (25, 35 and 45 degrees C). Biosorption showed pseudo second-order rate kinetics at different initial concentration of Pb(II) and different temperatures. The activation energy of the biosorption (E-a) was estimated as 59.04 kJ mol(-1) from Arrhenius equation. Using the equilibrium constant value obtained at different temperatures, the thermodynamic properties of the biosorption (Delta G degrees, Delta H degrees and Delta S degrees) were also determined. The results showed that biosorption of Pb(II) ions on C. albicans were endothermic and spontaneous. The optimum initial pH for Pb(II) was determined as pH 5.0. FTIR spectral analysis of Pb(II) adsorbed and unadsorbed C. albicans biomass was also discussed. (C) 2008 Elsevier B.V. All rights reserved.Öğe Production and characterization of neutral and alkaline protease from different Bacillus subtilis strains(Asian Journal Of Chemistry, 2008) Uyar, Fikret; Baysal, ZuebeydeAn extracellular neutral and alkaline protease from two different Bacillus subtilis strains were studied. The optimal activity occured when the pH level was 7.0 and 10.5 at a temperature of 35 and 45 degrees C for neutral protease and alkaline protease, respectively. When neutral protease was stable in the temperature range 35-60 degrees C, alkaline protease was found stable between 35-55 degrees C for 0.5 h. Divalent cations, especially Ca2+ increased enzymes activity and were inhibited by Mn2+,Ni2+, CU2+, Fe2+, Co2+, Cd2+ and Hg2+ for neutral protease and by Zn2+, Cd2+,Co2+, Cu2+ and Hg2+ for alkaline protease. The neutral protease was also inhibited by ethylenediamine-tetraacetic acid, 1, 10 phenanthroline and dithiothreitol whereas alkaline protease was inhibited with phenylmethyl-sulfonyl fluoride. The obtained K-m values were 2.28 x 10(-3) +/- 3.65 x 10(-4), 2.28 x 10(-4) +/- 4.21 x 10(-5) and 1.70 x 10(-4) +/- 5.18 x 10(-5) M for azocasein, BSA and casein for neutral protease, respectively. The K-m values with azocasein, BSA, casein, N-suc-Ala-Ala-Ala-pNA and N-cbz-Ala-Ala-Leu-pNA were 2.02 x 10(-3) +/- 7.3 x 10(-5), 2.13 x 10(-4) +/- 6.04 x 10(-5), 8.75 x 10(-4) +/- 1.36 x 10(-4), 1.71 x 10(-3) +/- 3.93 x 10(-4) and 2.64 x 10(-4) +/- 4.93 x 10(-5) for alkaline protease.Öğe Production of extracellular alkaline ?-amylase by solid state fermentation with a newly isolated Bacillus sp.(Taylor & Francis Inc, 2008) Baysal, Zuebeyde; Uyar, Fikret; Dogru, Mehmet; Alkan, HueseyinProduction of alkaline -amylase employing our laboratory isolate, Bacillus sp., under solid state fermentation, was optimized. The effect of wheat bran and lentil husk was examined. Lentil husk exhibited the highest enzyme production. The appropriate incubation time, inoculum size, moisture level, and buffer solution level were determined. Maximum yields of 216,000 and 172,800 U/g were achieved by employing lentil husk and wheat bran as substrates in 0.1 M carbonate/bicarbonate buffer at pH 10.0 with 30% initial moisture level at 24h. Inoculum size and buffer solution level were found to be 20% and 1:0.5 for two solid substrates.Öğe Screening of Various Organic Substrates and the Development of a Suitable Low-Cost Fermentation Medium for the Production of ?-Amylase by Bacillus subtilis(Faculty Food Technology Biotechnology, 2009) Ozdemir, Sadin; Guven, Kemal; Baysal, Zuebeyde; Uyar, FikretThe production of extracellular amylase by Bacillus subtilis has been studied in solid-state fermentation (SSF). In a sequential order, various process parameters were optimized for maximum amylase production. The tested process parameters were different solid substrates such as banana husk (BH), water melon husk (WMH), lentil bran (LB), wheat bran (WB), melon husk (MH) and maize oil cake (MOC), different incubation time (24-144 h), particle size (500-2500 mu m), initial moisture content of the substrate (40-70 %, by mass per Volume), inoclum size (10-60 %, by mass per volume) and inoculum concentration (10-60 % by volume per mass). The maximum production of amylase (4857 U/mg) was achieved when 1 % starch (by mass, particle size of 1500 pm) was added to banana husk as the solid substrate, fermented for 72 h at 37 degrees C, at an inoculum level of 30 % (by volume per mass), and initial moisture content of 60 % (by volume per mass)
