Yazar "Kilinc, Ersin" seçeneğine göre listele

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    Application of magnetized fungal solid phase extractor with Fe2O3 nanoparticle for determination and preconcentration of Co(II) and Hg(II) from natural water samples
    (Elsevier Science Bv, 2018) Ozdemir, Sadin; Mohamedsaid, Siham Abdullah; Kilinc, Ersin; Yildirim, Aydil; Soylak, Mustafa
    Pleurolus eryngii loaded Fe2O3 magnetic nanoparticles were developed as novel magnetic solid phase bio-extractors for the preconcentrations and extractions of Co(II) and Hg(II) from real samples. The metal binding surface groups of the prepared magnetic solid phase bio-extractors were investigated by FT-IR spectrometry, SEM and EDX. Several parameters influencing the magnetic extractions and preconcentrations of Co(II) and Hg (II) were examined and optimized, including pH, flow rate, quantity of P. eryngii, quantity of Fe2O3 magnetic nanoparticle, eluent type, concentration and volume, sample volume, and foreign ions. A good reusage (35 times) was obtained with the relative standard deviation (RSD) of < 5.0% for both magnetic solid phase bio-extractors. The biosorption capacities were determined for Co(II) and Hg(II) as 25.4 mg g(-1) and 30.3 mg g(-1), respectively, using P. eryngii loaded Fe2O3 magnetic nanoparticle column. The preconcentration factors for Co(II) and Hg(II) were found as 80 and 100, respectively, when using P. eryngii loaded Fe2O3 magnetic nanoparticle column. The developed procedures were validated through analysis of the certified reference materials and successfully utilized for the determinations of Co(II) and Hg(II) in real samples by inductively coupled plasma optical emission spectrometry (ICP-OES) with satisfactory results.
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    Bacillus sp immobilized on Amberlite XAD-4 resin as a biosorbent for solid phase extraction of thorium prior to UV-vis spectrometry determination
    (Springer Wien, 2010) Ozdemir, Sadin; Erdogan, Sait; Kilinc, Ersin
    A method has been developed for the preconcentration of Th prior to its determination by UV-vis spectrophotometry after complexation with Arsenazo Ill. A column was packed with Amber lite XAD-4 resin containing immobilized Bacillus sp. as a solid phase extractant. Parameters such as pH of the solution and sample, the concentration of Th, the volume and type of eluent, flow rate and effect of matrix interference were studied. The optimum pH for the sorption of Th is 5.0, and quantitative eluation occurs with 1 mol L-1 HCl. The tolerance limits of some electrolytes were also studied. The loading capacity was determined to be 17.2 mg g(-1) The method was applied to the determination of Th in real ore sample and validated by analyzing a certified reference samples (NCS DC-73350; poplar leaves).
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    Bioaccumulation, Resistance, Removal of U(VI) and Th(IV) and Their Effects on Antioxidant Enzymes on Thermophilic Anoxybacillus flavithermus ST15
    (Taylor & Francis Inc, 2022) Acer, Omer; Kilinc, Ersin; Ozdemir, Sadin
    In this research, a novel heavy metals resistance thermophilic Anoxybacillus flavithermus ST15 was isolated from a hot spring mud sample in Afyonkarahisar (Omer). 16S rRNA analyzing revealed that strain ST15 was 99.7% similar to Anoxybacillus flavithermus subsp. yunnanensis str. E13. We propose that U(VI) and Th(IV) have an effect on A. flavithermus at the cellular level and that this bacteria can be used as a bioindicator. Therefore, the effects of U(VI) and Th(IV) resistance, removal, and bioaccumulation on the antioxidant enzyme systems of thermophilic A. flavithermus have been thoroughly investigated. SOD and CAT activities were observed to be increased by different concentrations of U(VI) and Th(IV). A scanning electron microscope and fourier transform infrared spectroscopy were used to analyze changes in the surface macrostructure and functionality of A. flavithermus following interaction with U(VI) and Th(IV). The highest bioaccumulation efficiency amounts for U(VI) were 102.36 mg/g dried bacteria at 24 h at 12.5 mg/l concentration and 105.7 mg/g dried bacteria at 36 h at 12.5 mg/l concentration was detected for Th(IV). At the 24th h and 12.5 mg/l, the highest U(VI) and Th(IV) cell membrane bioaccumulation capacities of A. flavithermus were calculated as 307.08 and 289.52 mg metal/g wet membrane, respectively. This is the first research to examine U(VI) and Th(IV) resistance, removal, and bioaccumulation in thermophilic A. flavithermus.
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    Bioaccumulation, tolerance, and removal of U(VI) and Th(IV) by a novel thermophilic Bacillus cereus ST14 isolated from hot spring mud samples in Afyonkarahisar, Turkey
    (Springer Heidelberg, 2024) Ozdemir, Sadin; Acer, Omer; Kilinc, Ersin
    In this study, a novel thermophilic Bacillus cereus ST14 with heavy metal tolerance was isolated from a hot spring mud sample in Afyonkarahisar (Omer). 16S rRNA analysis revealed that strain ST14 was mostly related to Bacillus cereus strain 151,007-R3_K09_40_27F (98.18%) and Bacillus cereus strain 2 k (98.10%). We hypothesized that U(VI) and Th(IV) affected B. cereus at the cell level and that this bacterium can be used as a bioindicator. Therefore, U(VI) and Th(IV) tolerance, removal, bioaccumulation, and impacts on antioxidant enzymes of thermophilic B. cereus have been examined in detail. Changes in the surface macrostructure and functionality of B. cereus following interaction with U(VI) and Th(IV) were studied using a scanning electron microscope and fourier transform infrared spectroscopy. B. cereus was found to be highly resistant to 10 and 12.5 mg/L of U(VI) and Th(IV) after 24-h incubation. Superoxide dismutase (SOD) and catalase (CAT) activities were observed to be increased by different U(VI) and Th(IV) concentrations. The highest bioaccumulation capacity quantities were detected as 100.79 and 87.96 mg metal/g dried bacteria at 24th h at 12.5 mg/L concentration for U(VI) and Th(IV), respectively. The highest U(VI) and Th(IV) cell membrane bioaccumulation capabilities of B. cereus have been measured as 318.94 and 263.89 mg metal/g wet membrane, respectively, at 24 h and 12.5 mg/L. This study's findings suggested that B. cereus could be employed as a bioindicator organism for detecting metal contamination in natural or industrial water samples. However, further research should focus on other thermophilic microorganisms.
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    Biosorption of 2,4-d, 2,4-DP, and 2,4-DB from aqueous solution by using thermophilic anoxybacillus flavithermus and analysis by high-performance thin layer chromatography: Equilibrium and kinetic studies
    (Wiley, 2012) Ozdemir, Sadin; Bekler, Fatma Matpan; Okumus, Veysi; Dundar, Abdurrahman; Kilinc, Ersin
    In this study, the potential biosorption characteristics of the thermophilic Anoxybacillus flavithermus (A. flavithermus) was investigated for the removal of the chlorophenoxy acid derivates, namely, 2,4-dichlorophenoxy acetic acid (2,4-D), 2,4-dichlorophenoxy propanoic acid (2,4-DP or dichlorprop), and 2,4-dichlorophenoxy butyric acid (2,4-DB). The experiments were performed for the simultaneous biosorption of the studied pesticides. Optimum biosorption conditions were determined as a function of contact time, pH of the solution, amount of biomass, and initial pesticides concentrations. The concentrations of the pesticides in the remaining solutions were simultaneously analyzed by high performance thin layer chromatography. The optimum parameters were found as pH: 4.0 for biosorption medium, 60 min of contact time, 50 mg of bacteria, and 50 mg L-1 of initial pesticides concentrations. Langmuir and Freundlich models were applied to describe the biosorption isotherm of the pesticides by A. flavithermus as biomass. Biosorption of pesticides on to A. flavithermus showed pseudo first-order rate kinetics at different initial concentration of pesticides and different temperatures. The experimental adsorption data were fitted both the Langmuir and Freundlich adsorption models. Fourier-transform Infrared spectroscopy was used to understand the bonding mechanism of pesticides to biosorbent and surface functionality of the biosorbent The highest pesticide uptake was calculated from Langmuir isotherm and found to be 24.15 mg g-1 for 2,4-D. Among the studied pesticides, 2,4-DP showed difference adsorption behavior. According to in your comments the reason of this that 2,4-DP contain an asymmetric carbon atom, which provide a molecular chirality. (C) 2011 American Institute of Chemical Engineers Environ Prog, 2011
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    Biosorption of chlorophenoxy acid herbicides from aqueous solution by using low-cost agricultural wastes
    (Taylor & Francis Inc, 2015) Okumus, Veysi; Celik, K. Serdar; Ozdemir, Sadin; Dundar, Abdurrahman; Kilinc, Ersin
    The potential biosorption abilities of apple shell (AS), orange peel (OP), banana peel (BP), and millet waste (MW) as a bio-waste material to remove 2,4-dichlorophenoxy acetic acid (2,4-D), 2,4-dichlorophenoxy propanoic acid (2,4-DP), and 2,4-dichlorophenoxy butyric acid (2,4-DB) from aqueous solution were investigated in batch condition. Optimum biosorption conditions were determined as a function of contact time, pH of the solution, amount of biomass, and initial pesticide concentrations. The concentrations of the pesticides in the remaining solutions were simultaneously determined by high performance thin layer chromatography. Langmuir and Freundlich models were applied to describe the biosorption isotherm of the pesticides by agricultural wastes. The experimental adsorption data were fitted to Langmuir adsorption models (r(2)>0.99). It was found that adsorption of 2,4-DP was higher for all biosorbent. The highest maximum adsorption capacities of 2,4-DP were found as 40.08, 22.71, 33.26, and 45.45mg/g, respectively, for AS, OP, BP, and MW. Maximum adsorption capacity was obtained for 2,4-D as OP>MW>BP>AS, 2,4-DP as MW>AS>BP>OP, and 2,4-DB as OP>AS>BP>MW. From the results, it can be said that MW was an effective biosorbent for removal of 2,4-DP and OP was an effective biosorbent for removal of 2,4-D and 2,4-DB through the studied pesticides. Optimum biosorption conditions were determined as 60min of contact time, 100mg of biomass, AS at pH 6.0, OP at pH 6.0, MW at pH 7.0, and BP at pH 7.0. FT-IR was employed to understand the surface properties of biosorbents. According to the results, agricultural wastes have high adsorption capacity.
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    Biosorption of Heavy Metals (Cd2+, Cu2+, Co2+, and Mn2+) by Thermophilic Bacteria, Geobacillus thermantarcticus and Anoxybacillus amylolyticus: Equilibrium and Kinetic Studies
    (Taylor & Francis Inc, 2013) Ozdemir, Sadin; Kilinc, Ersin; Poli, Annarita; Nicolaus, Barbara
    Two strains of thermophilic bacteria, Geobacillus thermantarcticus and Anoxybacillus amylolyticus, were employed to investigate the biosorption of heavy metals including Cd2+, Cu2+, Co2+, and Mn2+ ions. The effects of different biosorption parameters such as pH (2.010.0), initial metal concentrations (10.0300.0mg L-1), amount of biomass (0.2510g L-1), temperature (3080 degrees C), and contact time (15120min) were investigated. Concentrations of metal ions were determined by using an inductively coupled plasma optical emission spectrometry (ICP-OES). Optimum pHs for Cd2+, Cu2+, Co2+, and Mn2+ biosorption by Geobacillus thermantarcticus were found to be 4.0, 4.0, 5.0, and 6.0, respectively. For Anoxybacillus amylolyticus, the optimum pHs for Cd2+, Cu2+, Co2+, and Mn2+ biosorption were found to be 5.0, 4.0, 5.0, and 6.0, respectively. The Cd2+, Cu2+, Co2+, and Mn2+ removals at 50mg L-1 in 60min by 50mg dried cells of Geobacillus thermantarcticus were 85.4%, 46.3%, 43.6%, and 65.1%, respectively, whereas 74.1%, 39.8%, 35.1%, and 36.6%, respectively, for Anoxybacillus amylolyticus. The optimum temperatures for heavy metal biosorption were near the optimum growth temperatures for both strains. Scatchard plot analysis was employed to obtain more compact information about the interaction between metal ions and biosorbents. The plot results were further studied to determine if they fit Langmuir and Freundlich models.
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    Comparative solid phase extraction study on the U(VI) preconcentration by using immobilized thermotolerant Bacillus vallismortis and Bacillus mojavensis
    (Springer, 2018) Ozdemir, Sadin; Oduncu, M. Kadir; Kilinc, Ersin; Soylak, Mustafa
    Bacillus vallismortis and Bacillus mojavensis were loaded onto Amberlite XAD-4 resin and used for solid phase extraction (SPE) of uranium(VI). A quick and simple UV-Vis spectrophotometric method was used to determine U(VI) ion. The best experimental conditions were determined as being a pH of 5.0; a sample flow rate of 2.0 mL min(-1); 200.0 mg of biosorbent; 800 mg of Amberlite XAD-4, and 5.0 mL of 1 mol L-1 HCl as desorption solution for both immobilized bacteria. The preconcentration factors were achieved as 80 for both solid phase extractor. The developed methods were validated by applying to reference water and tea samples.
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    Geobacillus thermoleovorans immobilized on Amberlite XAD-4 resin as a biosorbent for solid phase extraction of uranium (VI) prior to its spectrophotometric determination
    (Springer Wien, 2012) Ozdemir, Sadin; Kilinc, Ersin
    Geobacillus thermoleovorans subsp stromboliensis, was immobilized on an Amberlite XAD-4 ion exchanger and used as a solid phase extractant for the preconcentration of U(VI) ions prior to their determination by UV-VIS spectrophotometry. Parameters affecting the preconcentration (such as the pH value of the sample solution, the concentration of U(VI), the volume and type of eluent, the flow rate and the effect of potentially interfering ions) were studied. The optimum pH for the sorption of U(VI) was found to be pH 5.0. 5.0 mL of 1 M hydrochloric acid were used to eluate the U(VI) from the column. The loading capacity is 11 mg g(-1). The limits of detection and quantification are 2.7 and 9.0 mu g L-1, respectively, and relative standard deviations are < 10 %. The method was applied to the determination of U(VI) in a certified reference sample (NCS ZC-73014; tea leaves) and in natural water samples.
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    Investigations of Hg(II) and Pb(II) tolerance, removal and bioaccumulation and their effects on antioxidant enzymes on thermophilic Exiguobacterium profundum
    (Taylor & Francis Inc, 2020) Akkoyun, Mahire Bayramoglu; Ozdemir, Sadin; Kilinc, Ersin; Birhanli, Emre
    Hg(II) and Pb(II) tolerance, removal, bioaccumulation and effects on antioxidant enzymes of thermophilic Exiguobacterium profundum were investigated. The results indicated that Hg(II) was more toxic than Pb(II) to E. profundum. E. profundum was also more tolerant in solid medium than in liquid medium for Pb(II) and Hg(II). The bacterial growth was not significantly influenced at 1.0 and 2.5 mg/L Pb(II) and Hg(II) for 24 h. The highest Hg(II) and Pb(II) bioaccumulation amounts were determined as 37.56 and 54.35 mg metal/dried bacteria, respectively. Bioaccumulation capacities of the cell membrane of E. profundum for Hg(II) and Pb(II) were determined. The different concentrations of Pb(II) and Hg(II) enhanced the SOD and CAT enzymes. In addition, variations of the surface macrostructure and the functionality of E. profundum after the interaction with Hg(II) and Pb(II) were investigated by the scanning electron microscope (SEM) and the Fourier transform infrared spectroscopy (FT-IR), respectively. This investigation obviously showed that thermophilic E. profundum can also be applied for removal and recovery of toxic metals from industrial wastewater. Clearly, a further investigation should be utilized by thermophilic microorganisms. According to antioxidant enyzme activities, E. profundum can be also used as a bioindicator for the detection of toxic metal pollution in natural water samples.
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    Magnetic solid phase extractions of Co(II) and Hg(II) by using magnetized C-micaceus from water and food samples
    (Elsevier Sci Ltd, 2019) Ozdemir, Sadin; Mohamedsaid, Siham Abdullah; Kilinc, Ersin; Soylak, Mustafa
    A new bio-MSPE sorbent based on the use of C. micaceus and gamma-Fe2O3 magnetic nanoparticle was prepared for the preconcentrations of Co(II) and Hg(II). Critical parameters including pH, flow rate, quantity of C. micaceus, quantity of gamma-Fe2O3 magnetic nanoparticle, eluent (type, concentration and volume), sample volume, and foreign ions were examined. Surface structure and variations after interaction with Co(II) and Hg(II) of bio-MSPE sorbent were investigated by FT-IR, SEM, and EDX. The impact of bio-MSPE column reusage was also tested. The biosorption capacities were determined as 24.7 mg g(-1) and 26.2 mg g(-1), respectively for Co(II) and Hg(II). Certified reference materials were utilized to find out the accuracy of the prepared bio-MSPE method. This novel bio-MSPE method was accomplished by being applied to real food and water samples. In particular, it will be possible to make use of C. micaceus as new alternatives, in environmental biotechnology applications.
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    Phallus impudicus loaded with ?-Fe2O3 as solid phase bioextractor for the preconcentrations of Zn(II) and Cr(III) from water and food samples
    (Elsevier Sci Ltd, 2020) Yalcin, M. Serkan; Kilinc, Ersin; Ozdemir, Sadin; Yuksel, Uyan; Soylak, Mustafa
    We investigated the application of fungus Phallus impudicus loaded gamma-Fe2O3 nanoparticles as a biosorbent for magnetic solid phase extractions of trace levels of Zn(II) and Cr(III) ions from natural samples before their measurements by inductively coupled plasma optical emission spectrometry. The characterization of magnetized P. impudicus was performed using the scanning electron microscope, the energy dispersive X-ray and Fourier transform infrared spectroscopy. Important experimental factors were investigated. The experimental results fitted well to the Langmuir adsorption model and pseudo-second order kinetic model. Limit of detections of targeted ions by magnetic solid phase extraction method based on use of P. impudicus were found as 10.5 ngL(-1) and 12.6 ngL(-1) respectively for Cr(III) and Zn(II). The sorption capacities of the biosorbent were 22.8 mgg(-1) for Cr(III) and 25.6 mgg(-1) for Zn(II). The preconcentration factors were achieved as 100 for both of ions. RSDs for inter- and intraday precisions were found as lower than 2.0% and 2.1% respectively for both of targeted ions. The accuracy of the recommended process was tested by recovery measurements on the certificated reference materials and successfully applied for quantification recoveries of Cr(III) and Zn(II) ions from water and food samples.
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    Pleurotus eryngii immobilized Amberlite XAD-16 as a abstract insert solid-phase biosorbent for preconcentrations of Cd2+ and Co2+ and their determination by ICP-OES (vol 99, pg 502, 2012)
    (Elsevier Science Bv, 2013) Ozdemir, Sadin; Okumus, Veysi; Kilinc, Ersin; Bilgetekin, Havin; Dundar, Abdurrahman; Ziyadanogullari, Berrin
    [Abstract Not Available]
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    Preconcentration of cadmium and nickel using the bioadsorbent Geobacillus thermoleovorans subsp stromboliensis immobilized on Amberlite XAD-4
    (Springer Wien, 2010) Ozdemir, Sadin; Gul-Guven, Reyhan; Kilinc, Ersin; Dogru, Mehmet; Erdogan, Sait
    Cadmium and nickel ions have been preconcentrated on Geobacillus thermoleovorans subsp. stromboliensis, immobilized on Amberlite XAD-4, and were determined by flame atomic absorption spectrometry (FAAS). Parameters such as pH, amount of adsorbent, eluent type and volume, flow rate of solution and the matrix interference effect on retention have been studied, and extraction conditions were optimized. Elution of Cd(II) and Ni(II) from minicolumns was carried out with 1.0 M hydrochloric acid or nitric acid with recoveries from 97 to 100%. The sorption capacity is 0.0373 and 0.0557 mmol g(-1) for Cd(II) and Ni(II), respectively. The detection limits were 0.24 mu g L-1 for cadmium and 0.3 mu g L-1 for nickel. The relative standard deviations of the procedure were below 10%. The procedure was validated by analyzing certified reference materials and applied to the determination of Cd(II) and Ni(II) in natural water and food samples.
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    Preconcentration with Bacillus subtilis-Immobilized Amberlite XAD-16: Determination of Cu2+ and Ni2+ in River, Soil, and Vegetable Samples
    (Taylor & Francis Inc, 2015) Okumus, Veysi; Ozdemir, Sadin; Kilinc, Ersin; Dundar, Abdurrahman; Yuksel, Uyan; Baysal, Zubeyde
    Solid-phase extraction (SPE) method was developed for the preconcentration of Cu2+ and Ni2+ before their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). Bacillus subtilis-immobilized Amberlite XAD-16 was used as biosorbent. Effects of critical parameters such as pH, flow rate of samples, amount of Amberlite XAD-16 and biosorbent, sample volume, eluent type, and volume and concentration of eluent on column preconcentration of Cu2+ and Ni2+ were optimized. Applicability of the method was validated through the analysis of the certified reference tea sample (NCS ZC73014). Sensitivity of ICP-OES was improved by 36.4-fold for Cu2+ and 38.0-fold for Ni2+ by SPE-ICP-OES method. Limit of quantitation (LOQ) was found to be 0.7 and 1.1ng/ml for Cu2+ and Ni2+, respectively. Concentrations of Cu2+ and Ni2+ were determined by ICP-OES after application of developed method. Relative standard deviations (RSDs) were lower than 4.9% for Cu2+ and 7.9% for Ni2+. The Tigris River that irrigates a large agricultural part of Southeast Turkey is polluted by domestic and industrial wastes. Concentrations of Cu2+ and Ni2+ were determined in water, soil, and some edible vegetables as a biomonitor for heavy metal pollution.
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    Preconcentrations of Zn(II) and Hg(II) in Environmental and Food Samples by SPE on B. licheniformis Loaded Amberlite XAD-4
    (Springernature, 2022) Ozdemir, Sadin; Kilinc, Ersin; Acer, Omer; Soylak, Mustafa
    In this work, the separations and preconcentrations of Zn(II) and Hg(II) ions on Bacillus lichenifoemis loaded onto Amberlite XAD-4 resin by solid-phase extraction has been performed. The biosorbent was characterized by using FT-IR, SEM, and EDX. pH, sample flow rate, eluent type and concentration, amount of B. licheniformis and XAD-4 resin, sample volume, and possible interfering ions effect were investigated in details as experimental variables in the SPE procedure. Limit of detection values for Zn(II) and Hg(II) were detected as 0.03 and 0.06 ng-mL(-1), respectively. 0.2-15 ng-mL(-1) linear range values were achieved for Zn(II) and Hg(II), respectively. Relative standard deviation values were found to be lower than 5%. For validation of the procedure, the certified standard reference materials (CWW-TM-D, EU-L-2, NCS ZC73O14, NCS ZC73350) were analyzed. The concentrations of Zn(II) and Hg( II) in water and food samples were measured by ICP-OES. Consequently, it can be inferred that the immobilized B. licheniformis microcolumn has ideal selectivity for Zn(II) and Hg(II) biosorption.
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    Resistance and bioaccumulation of Cd2+, Cu2+, Co2+ and Mn2+ by thermophilic bacteria, Geobacillus thermantarcticus and Anoxybacillus amylolyticus
    (Springer, 2013) Ozdemir, Sadin; Kilinc, Ersin; Nicolaus, Barbara; Poli, Annarita
    In this study, bioaccumulation and heavy metal resistance of Cd2+, Cu2+, Co2+ and Mn2+ ions by thermophilic Geobacillus thermantarcticus and Anoxybacillus amylolyticus was investigated. The bacteria, in an order with respect to metal resistance from the most resistant to the most sensitive, was found to be Mn2+ > Co2+ > Cu2+ > Cd2+ for both G. thermantarcticus and A. amylolyticus. It was determined that the highest metal bioaccumulation was performed by A. amylolyticus in Mn2+ (28,566 mu g/g dry weight), and the lowest metal bioaccumulation was performed by A. amylolyticus in Co2+ (327.3 mu g/g dry weight). The highest Cd2+ capacities of dried cell membrane was found to be 36.07 and 39.55 mg/g membrane for G. thermantarticus and A. amylolyticus, respectively, and the highest Cd2+ capacities of wet cell membrane was found to be 14.36 and 12.39 mg/g membrane for G. thermantarcticus and A. amylolyticus, respectively.
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    Resistance, bioaccumulation and solid phase extraction of uranium (VI) by Bacillus vallismortis and its UV-vis spectrophotometric determination
    (Elsevier Sci Ltd, 2017) Ozdemir, Sadin; Oduncu, M. Kadir; Kilinc, Ersin; Soylak, Mustafa
    Bioaccumulation, resistance and preconcentration of uranium(VI) by thermotolerant Bacillus vallismortis were investigated in details. The minimum inhibition concentration of (MIC) value of U(VI) was found as 85 mg/L and 15 mg/L in liquid and solid medium, respectively. Furthermore, the effect of various U(VI) concentrations on the growth of bacteria and bioaccumulation on B. vallismortis was examined in the liquid culture media. The growth was not significantly affected in the presence of 1.0, 2.5 and 5.0 mg/L U(VI) up to 72 h. The highest bioaccumulation value at 1 mg/L U(VI) concentration was detected at the 72nd hour (10 mg/g metal/dry bacteria), while the maximum bioaccumulation value at 5 mg/L U(VI) concentration was determined at the 48th hour (50 mg metal/dry bacteria). In addition to these, various concentration of U(VI) on alpha-amylase production was studied. The alpha-amylase activities at 0, 1, 2.5 and 5 mg/L U(VI) were found as 3313.2, 3845.2, 3687.1 and 3060.8 U/mg, respectively at 48th. Besides, uranium (VI) ions were preconcentrated with immobilized B. vallismortis onto multiwalled carbon nanotube (MWCNT) and were determined by UV-vis spectrophotometry. The surface macro structure and functionalities of B. vallismortis immobilized onto multiwalled carbon nanotube with and without U(VI) were examined by FT-IR and SEM. The optimum pH and flow rate for the biosorption of U(VI) were 4.0-5.0 and 1.0 mL/min, respectively. The quantitative elution occurred with 5.0 mL of 1 mol/L HCI. The loading capacity of immobilized B. vallismortis was determined as 23.6 mg/g. The certified reference sample was employed for the validation of developed solid phase extraction method. The new validated method was applied to the determination of U(VI) in water samples from Van Lake-Turkey. (C) 2017 Elsevier Ltd. All rights reserved.
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    Resistance, removal, and bioaccumulation of Ni (II) and Co (II) and their impacts on antioxidant enzymes of Anoxybacillus mongoliensis
    (Elsevier Science Inc, 2020) Akkoyun, Mahire Bayramoglu; Ozdemir, Sadin; Kilinc, Ersin; Birhanli, Emre; Aygun, Aysenur; Sen, Fatih
    In this study, it was hypothesis that A. mongoliensis could be used as bioindicator for Ni (II) and Co (II). Thus, Ni (II) and Co (II) resistance, removal, bioaccumulation, and the impacts of them on antioxidant enzyme systems of thermophilic Anoxybacillus mongoliensis were investigated in details. The bioaccumulation of Ni (II) and Co (II) on the cell membrane of thermophilic A. mongoliensis, variations on surface macrostructure and functionality by FT-IR and SEM, and determination of antioxidant enzyme activities were also tested. The highest bioaccumulation values of Co (II) and Ni (II) were detected as 102.0 mg metal/g of dry bacteria at 10 mg/L for the 12th h and 90.4 mg metal/g of dry bacteria for the 24th h, respectively, and the highest Ni (II) and Co (II) cell membrane bioaccumulation capacities of A. mongoliensis were determined as 268.5 and 274.9 mg metal/g wet membrane, respectively at the 24th h. In addition, increasing on SOD and CAT activities were observed on depend of concentration of Ni (II) and Co (II) with respect to control. The antioxidant enzyme activity results also indicated that A. mongoliensis might be used as a bioindicator for Ni (II) and Co (II) pollution in environmental water specimens.
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    Selective preconcentration of Lanthanum(III) by Coriolus versicolor immobilised on Amberlite XAD-4 and its determination by ICP-OES
    (Taylor & Francis Ltd, 2014) Ozdemir, Sadin; Okumus, Veysi; Dundar, Abdurrahman; Celik, Kadir Serdar; Yuksel, Uyan; Kilinc, Ersin
    Coriolus versicolor, a wood fungus, was immobilised on Amberlite XAD-4 and used as solid-phase biosorbent for preconcentrations of rare earth elements. La(III), Th(IV), U(IV) and Ce(III) were subjected to solid-phase extraction procedure. We observed that La(III) was selectively preconcentrated, while other ions remained in solution at pH 6.0. 5.0mL of 1.0molL(-1) HCl was used to elaute La(III) from column. 250mg of C. versicolor loaded on 1000mg of XAD-4 was optimised as solid-phase matrix. Concentrations of ions in solutions were determined by inductively coupled plasma- optical emission spectrometry (ICP-OES). The calibration plot after preconcentration was linear in the range from 1.0 to 50.0ngmL(-1) for La(III). Limit of detection was found as 0.27ngmL(-1) for La(III) by SPE method. Relative standard deviation was found lower than 6.7% for 1.0ngmL(-1) of La(III) solution (n=10). The sensitivity of ICP-OES was improved by a factor of 46.8. The applicability of the method was validated through the analysis of certified reference samples of tea (NCS ZC-73014) and spinach (NCS ZC-73013).