Abdurrahman Dündar

Preconcentration of metal ions using microbacteria

AbstractThis review (160 refs). covers the current state of the art of microbacteria-based sorbents for preconcentration of metal ions at trace levels. We highlight advantages and major challenges of the techniques and discuss future perspectives of both batch and column-based methods. Particular attention is paid to the preconcentration of metal ions using resin-immobilized microbacteria for solid phase extractions. We also discuss detection methods including UV–vis spectrophotometry, FAAS, ICP-OES and ICP-MS. Analytical figures of merit are compared, and examples are given for the application to a variety of samples including food, beverages, alloys, water, soil, and geological samples. FigureAn graphical presentation of main experimental steps in solid phase extraction procedure for metal ions together with the summarization of affinity of metal ions to functional groups on the surface of bacteria by considering the classifications according to hard and soft acids and bases theory by Pearson

Pleurotus eryngii immobilized Amberlite XAD-16 as a solid-phase biosorbent for preconcentrations of Cd2+ and Co2+ and their determination by ICP-OES.

This article reports a method that is used for the preconcentration and determination of Cd(2+) and Co(2+) in vegetables, using Pleurotus eryngii immobilized Amberlite XAD-16 as a solid-phase biosorbent. The concentrations of metals were determined by inductively coupled plasma-optical spectrometry (ICP-OES). Critical parameters, such as the pH of the solution, flow rate, the amount of biosorbent, type and volume of eluent, and the sample volume, that affect the solid-phase extraction (SPE) procedure were optimized. The optimum extraction conditions were determined as being a pH of 6.0 for Cd(2+) and of 5.0 for Co(2+); a sample flow rate of 2.0 mL min(-1); 200.0mg of biosorbent; and 5.0 mL of 1.0 mol L(-1) HCl as eluent. The capacities of the biosorbent for metal uptake were found to be 11.3 and 9.8 mg g(-1) for Cd(2+) and Co(2+) ions, respectively. Limit of quantitations (LOQs) were found to be 0.67 and 0.82 ng mL(-1), respectively, for Cd(2+) and Co(2+). The linear working curves were observed to be in the linear range from 1.0 to 50.0 ng mL(-1), and possessed high correlation coefficients. The use of the SPE method showed 50.7- and 35.7-fold improvements in the sensitivities of ICP-OES. The developed method was successfully applied to NCS ZC-73014 (a certified reference tea sample). Relative standard deviations (RSD) were lower than 5.0%. The Cd(2+) and Co(2+) concentrations in the different parts (leave, root, stem, and fruit) of purslane, onion, rocket, okra, and aubergine were determined after microwave digestion and solid-phase extraction by P. eryngii immobilized on Amberlite XAD-16.

Antioxidant properties, chemical composition and nutritional value of Terfezia boudieri (Chatin) from Turkey.

Our objectives were to investigate the chemical composition, nutritive value and antioxidant activity potentials of Terfezia boudieri Chatin collected from different areas from Southeast of Turkey. The amounts of energy, protein, fat, carbohydrate, crude fibre, moisture and ash were 34.00–65.00 (kcal/100 g), 1.40–2.73, 0.86–1.71, 4.84–11.60, 80.86–90.33 (g/100 g, f.w.) and 1.02–1.98 g/100 g dry mass, respectively. Fatty acids and amino acids analyses revealed that linoleic acid and glutamic acid were, respectively the most abundant. Among the essential amino acids leucine was the highest amount and this was followed by threonine. Magnesium was the most abundant element with a concentration value of 182.30 mg/100 g dry mass. T. boudieri exhibited excellent antioxidant activity when compared with standard compounds. In total antioxidant and chelating effect on ferrous ions activity T. boudieri showed the highest activity against the standards. Additionally, at all studied tests antioxidant activity of the mushroom increased with increasing concentration. The total phenolic content of T. boudieri was found as 8.45 mg/g.

Selective preconcentration of Lanthanum(III) by Coriolus versicolor immobilised on Amberlite XAD-4 and its determination by ICP-OES

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. 5.0 mL of 1.0 mol L−1 HCl was used to elaute La(III) from column. 250 mg of C. versicolor loaded on 1000 mg 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 50.0 ng mL−1 for La(III). Limit of detection was found as 0.27 ng mL−1 for La(III) by SPE method. Relative standard deviation was found lower than 6.7% for 1.0 ng mL−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).

Preconcentration with Bacillus subtilis–Immobilized Amberlite XAD-16: Determination of Cu2+ and Ni2+ in River, Soil, and Vegetable Samples

ABSTRACT 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 1.1 ng/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.

Anoxybacillus sp. SO B1–Immobilized Amberlite XAD-16 for Solid-Phase Preconcentration of Cu(II) and Pb(II) and Their Determinations by Flame Atomic Absorption Spectrometry

ABSTRACT A new method for the determination of Cu(II) and Pb(II) by flame atomic absorption spectrometry (FAAS) after preconcentrating on a column containing Anoxybacillus sp. SO B1–immobilized Amberlite XAD-16 was developed. The functional groups of Anoxybacillus sp. SO B1 immobilized on Amberlite XAD-16 were characterized in KBr tablets by Fourier transform infrared (FT-IR) spectrometry. Various parameters such as pH, amount of the adsorbent, eluent type and volume, and flow rate of the sample solution were studied. The optimum pH values of quantitative sorption for Cu(II) and Pb(II) were found to be pH 7.0 and 5.0 and Cu(II) and Pb(II) ions could be quantitatively eluted with 5.0 ml of 1.0 mol L−1 HCI and 10.0 ml of 0.25 mol L−1 HNO3, respectively. Recoveries of Cu(II) and Pb(II) were found to be 100.9 ± 1.57% and 100.3 ± 0.49% (N = 5), the limits of detection of Cu(II) and Pb(II) in the determination by FAAS (3 s, N = 10) were found to be 0.8 and 1.6 μg L−1, respectively. The proposed enrichment method was applied for metal ion determination from water samples such as two parts of Tigris River water in Diyarbakır and Elazığ, Lake of Hazar in Elazığ, and tap water in Diyarbakır. Furthermore, the accuracy of the proposed method was verified by studying the analytical recovery and by analyzing certified reference material (NCS-DC 73350 leaves of poplar).

The Use of Fungal Biomass Agaricus bisporus Immobilized on Amberlite XAD-4 Resin for the Solid-Phase Preconcentration of Thorium

ABSTRACT Solid-phase extraction method was developed for the preconcentration of thorium (Th). Fungal biomass Agaricus bisporus was immobilized to Amberlite XAD-4 as solid-phase sorbent. The critical parameters such as pH of the sample solution, flow rate of the sample, volume of the sample, and the effect of major ions that affect the preconcentration of thorium in this system were evaluated. The optimum pH for the sorption of Th is 6.0, and quantitative elution occurs with 1.0 mol L−1HCl. The loading capacity was determined as 0.079 mmol g−1. The optimized method was validated through analysis of the certified reference material of tea leaves (NCS ZC73014) and successfully applied to the determination of Th in a real ore sample with satisfactory results.

Antioxidant Properties of Cultured Mycelia from Four Pleurotus Species Produced in Submerged Medium

The ethanolic extracts of dried cultured mycelia of Pleurotus ostreatus, Pleurotus eryngii, Pleurotus florida, and Pleurotus sajor-caju were analyzed for antioxidant activity in different systems. Tests used are as follows: reducing power, free radical scavenging, superoxide anion radical scavenging, total antioxidant activity, metal chelating activitiy, etc.; total phenolic content was determined. The percentage inhibition of P. ostreatus, P. eryngii, P. florida, and P. sajor-caju at 20 mg/mL concentration on peroxidation in a β-carotene–linoleic acid system was 57.19, 60.68, 62.12, and 58.81%, respectively. The reducing power of P. eryngii was higher than the other samples, and its value was 0.86 at 10 mg/mL concentration. P. ostreatus and P. sajor-caju proved to be better at scavenging superoxide anion radicals than the P. eryngii and P. florida. In the scavenging effect of DPPH radical test, P. ostreatus showed the highest activity potential and P. sajor-caju showed the strongest metal chelating capacity.

Isolation of a Novel Thermophilic Anoxybacillus flavithermus SO-13, Production, Characterization and Industrial Applications of its Thermostable α-Amylase

In this research paper, a novel thermophilic bacteria named strain SO-13 was isolated from hot spring mud sample in Afyonkarahisar (Omer). Based on morphological and biochemical tests, 16S rRNA gene sequence analysis, G-C content and DNA-DNA hybridization analysis, the thermophilic isolate belonged to Anoxybacillus genus and it was closely related to A. flavithermus. The effects of different solid state fermentation conditions such as different substrate, incubation time, temperature, pH and surfactants on α-amylase production were experimented. In addition to these, different parameters such as temperature and temperature stability, pH and pH stability, detergents and surfactants, different starches and metal ions on effect of partially purified enzyme characterization were examined. The optimum temperature and pH of thermostable α-amylase was 80°C and 7.0, respectively. Thermostable α-amylase hydrolyzed the 76% and 87% of soluble starch content in red and green apple juice at 80°C in 30 min.

Antioxidant, Antimicrobial, Cytotoxic and Anticholinesterase Activities of SevenMushroom Species with their Phenolic Acid Composition

The study focused to evaluate cytotoxic, antioxidant, antimicrobial and anticholinesterase activities of methanol extracts of Pleurotus ostreatus Jacq. (Pleurotaceae), Boletus edulis Bull. (Boletaceae), Tricholoma populinum J. (Tricholomataceae) Helvella queletii Bres. (Helvellaceae), Armillaria tabescens Emel. (Physalacriaceae), Psathyrella candolleana Fr. (Psathyrellaceae) and Helvella leucopus Pers. (Helvellaceae) mushroom species. Phenolic acid profiles of these mushrooms were also determined to obtain further information on the correlation between the contents of phenolic compounds and studied activities. Cytotoxic activity of mushrooms was screened by MTT cytotoxicity assay on cancer (HeLa) and normal epithelium (NRK-52E) cell lines. To determine antioxidant potential of mushroom extracts free radical scavenging, reducing power, superoxide anion radical scavenging, total antioxidant and metal chelating activities were studied, To indicate anthicholinesterase activity the acetyl-and butyrylcholinesterase inhibitory activities of the mushroom extracts were studied. For antimicrobial activity disc diffusion method was applied. Phenolic profile of mushrooms were determined by HPLC system. The IC50 values of the extracts were 1.58-25.11 and 2.05-22.32 mg/mL for HeLa and NRK-52E cells, respectively. At antimicrobial activity the inhibiton zones were found to be as 1 ± 0.12-13 ± 0.23 mm. P. ostreatus, B. edulis and H. leucopus extracts were showed higher activities than the other mushroms at antioxidant, antimicrobial, anticholinesterase and cytotoxic activity.