Yazar "Nadaroglu H." seçeneğine göre listele
Listeleniyor 1 - 7 / 7
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Bacteria-modified red mud for adsorption of cadmium ions from aqueous solutions(2013) Kalkan E.; Nadaroglu H.; Dikbaş N.; Taşgin E.; Çelebi N.Cadmium is a toxic metal widely used in industry and it enters the environment from electroplating, smelting, alloy manufacturing, pigments, plastics, cadmium-nickel batteries, fertilizers, pesticides, mining, pigments and dyes, textile operations, and refining industries. Considering the harmful effects of cadmium, it is necessary to remove cadmium from liquid wastes at least to the limit accepted by regulations. The present study describes removal of cadmium from aqueous solutions using bacteria-modified red mud waste material. Batch adsorption experiments have been performed as a function of pH, contact time, temperature, and adsorbent dosage. The optimum results were obtained at pH 4.0, contact time of 60 min, temperature of 30°C, and an adsorbent dose of 1 mg/mL. The adsorption data was correlated with Langmuir and Freundlich adsorption models. The maximum adsorption capacity obtained from Langmuir adsorption model was 83.034 mg/g. The kinetic processes of cadmium adsorption on bacteria-modified red mud were described by applying pseudo-first-order and pseudo-second-order rate equations. The kinetic data for the adsorption process obeyed pseudo-second-order rate equations. Various thermodynamic parameters, such as ?G°, ?H°, and ?15° were calculated and the negative value of ?G° obtained indicate that the process was spontaneous, and the positive value of ?H° confirms the reaction to be endothermic, and the positive value of ?S° shows that the decrease in the degree of freedom of the adsorbed species. The bacteria-modified red mud investigated in this study exhibited a high potential for the removal of cadmium from aqueous solutions.Öğe Experimental study to remediate acid fuchsin dye using laccase-modified zeolite from aqueous solutions(HARD Publishing Company, 2015) Kalkan E.; Nadaroglu H.; Celebi N.; Celik H.; Tasgin E.This paper studies, the removal of acid fuchsin dye from aqueous solutions using zeolite natural material after its modification with laccase from Russulaceae (Lactarius volemus). Batch adsorption experiments were performed as a function of pH, contact time, temperature, and adsorbent dosage. The optimum results were obtained at pH 5, contact time of 60 min, temperature of 60ºC, and an adsorbent dosage of 1.5 mg/mL. The isotherm studies show that the adsorption experimental data are fitted well by Langmuir isotherm model. The adsorption capacity found is 31 mg/g. The kinetics of AFD adsorption on LMZ is best described with the pseudo-first-order kinetics model. Thermodynamic parameters including Gibbs free energy, enthalpy, and entropy changes indicate that the adsorption of Acid Fuchsin dye onto laccase-modified zeolite is feasible, spontaneous, and exothermic. The results show that laccase-modified zeolite can be used as an alternative lowcost adsorbent for dye removal from aqueous solutions. © 2015, HARD Publishing Company. All rights reserved.Öğe Purification and characterisation of laccase from lactarius volemus and its application in removal of phenolic compounds from fruit juice(WFL Publisher Ltd., 2013) Nadaroglu H.; Tasgin E.Laccases are multicopper oxidases (EC 1.10.3.2.), widely distributed in fungi, higher plants and bacteria. In this research, a laccase from Lactarius volemus (Russulaceae) was purified by 73.08 fold using precipitate of saturation (NH4)2SO4, DEAE-cellulose and Sephacryl S200. It was shown that purified enzyme was homogeneous in term of SDS-PAGE with molecular mass estimated of 30 kDa. The pH was optimal at 4.0, enzyme was stable at pH 3.0-5.0 and optimal temperature was at 50°C. Cu2+ and Fe2+ were activated to the purified laccase enzyme, and it was partially inhibited by 5 mM concentration of some metal salts and EDTA, urea, SDS, L-cysteine, dithioeritritol and ?-mercaptoethanol. In addition, it was investigated whether the purified and characterized laccase enzyme would remove the phenolic compound of some fruit juices which are responsible for haze formation and browning during storage. Their application led to reduction of total phenolic compounds for apple, apricot, cherry and grape juice. As a result, the effect of these enzymatic treatments on total phenol content and clarity of the juice were evaluated using a central composite design. This laccase enzyme had potential application in food processing.Öğe Purification and characterization of a pectin lyase produced by Geobacillus stearothermophilus Ah22 and its application in fruit juice production(2011) Demir N.; Nadaroglu H.; Tasgin E.; Adiguzel A.; Gulluce M.Extracellular pectin lyase (PL) (EC 4.2.2.10) was produced by Geobacillus stearothermophilus Ah22 in solid state fermentation. The PL enzyme was purified 40.8-fold by DEAE-cellulose anion exchange column chromatography and characterized. The molecular weight of the enzyme was determined as 36 kDa by Sephadex G-100 gel filtration chromatography. Purification of the enzymewas verified by SDS-PAGE. The optimumpHand temperature of the enzyme were determined as pH 6.0 and 60°C, respectively. The PL was mostly stable at 40°C. Its activity deceased by 50% after 2 h at 60°C and by 60% after 6 h at 50°C. The V max and K m were calculated as 0.47 mg/mL and 355.3 ?mol/L•min, respectively. The presence of 10 mM Ca 2+, Cu 2+, Mn 2+, Mg 2+, Zn 2+, Hg 2+, Fe 2+ and EDTA, L-cysteine and ascorbic acid significantly enhanced enzyme activity. The purified PL enzyme was used in the production of fruit juices; yields of fruits juice improved significantly compared with controls. © 2011 Springer-Verlag and the University of Milan.Öğe Purification and characterization of an alkaline pectin lyase produced by a newly isolated brevibacillus borstelensis (p35) and its applications in fruit juice and oil extraction(Springer Verlag, 2014) Demir N.; Nadaroglu H.; Demir Y.; Isik C.; Taskin E.; Adiguzel A.; Gulluce M.An alkaline pectin lyase (Pnl) (EC 4.2.2.10) secreted by Brevibacillus borstelensis P35 (genBank number: FJ417406) was purifed using ammonium sulfate fractionation, anion exchange chromatography on DEaE-cellulose and gel fltration chromatography on Sephadex g-150. The pH and temperature optima of the enzyme were found to be 8.0 and 60 °C. The enzyme does not loose activity up to 60 °C if exposed for 1 h. The values of Kmand Vmax of the enzyme were 0.625 mg/ml and 126.32 s-1, respectively. The molecular weight was found to be 36 ± 01 kDa. The presence of 10 mM concentration of Ca2+, Cu2+, Mn2+, Mg2+, Zn2+, Hg2+, Fe2+ and EDTa, L-cystein, ascorbic acid signifcantly enhanced the Pnl of the purifed enzyme. In the course of the laboratory trials, it was demonstrated that Pnl from B. borstelensis (P35) could be successfully applied to the production and clarif-cation of fruit juice and oil extraction. © Springer-Verlag Berlin Heidelberg 2014Öğe Purification and properties of carbonic anhydrase from bone marrow(2009) Tasgin E.; Nadaroglu H.; Demir Y.; Demir N.In this work, the carbonic anhydrase was purified from bovine bone marrow and investigated its kinetic properties. Carbonic anhydrase was purified from bovine bone marrow using affinity chromatography by sepharose 4B-L-tyrosine sulphanilamide. During purification steps, the activity of enzyme was measured using p-nitrophenyl acetate at pH: 7.4. Optimum pH and optimum temperature values for bovine bone marrow carbonic anhydrase were determined and then K m and Vmax values for the same substrate were obtained by means of Linewearver-Burk graphics. The purification degree for bovine bone marrow was calculated. The Vmax, and Km values at optimum pH and at 20 °C for the substrate (p-nitrophenyl acetate) were 120.418 u?mol/L min and 2.409 x 103 mM, respectively. The K1 and I50 values for sulfanilamide, KSCN, NaN3 and acetazolamide were determined in bovine bone marrow carbonic anhydrase.Öğe Purification of paraoxonase enzyme from the sera of patients with behcet’s disease and analyzing the effects of the drugs containing imuran (azathioprine), prednisolone (methylprednisolone) and colchium (colchicine)(Bentham Science Publishers B.V., 2014) Demir N.; Nadaroglu H.; Ozkan A.; Tasgin E.; Isik C.; Demir Y.In this study, serum samples from 50 patients with the diagnosis of Behcet’s disease and 20 healthy volunteers were analyzed. The study consists of three parts. In the first part, paraoxonase (PON) activities were determined in the serum samples of 50 patients with Behcet’s disease and 20 healthy people. In the second part, equal volumes of serum samples from 50 patients were pooled and PON enzymes were purified by using Sepharose-4B-L-tyrosine tyrosine-1-naphtylamine affinity column. Optimum temperature, optimum pH, Vmax and Km values of the pure enzymes were determined. The same purification procedure was also performed in the serum samples of 20 healthy people. Electrophoretic mobility was observed (via SDS-PAGE) in the PON enzymes that were purified from the serum samples of patients with Behcet’s disease and healthy people. In the third part, in vitro effects of drugs containing azathioprine, methylprednisolone and colchicine that have already been used for the treatment of Behcet’s disease were tested on the PON enzymes of the patients with Behcet’s disease and control group. IC50 values and Ki constant values were measured and inhibition types were determined for the drugs containing azathioprine, methylprednisolone and colchicine that have already been used for the treatment of the Behcet’s disease and demonstrate in vitro inhibition effects. ©2014 Bentham Science Publishers.
