Investigations of Hg(II) and Pb(II) tolerance, removal and bioaccumulation and their effects on antioxidant enzymes on thermophilic Exiguobacterium profundum

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.This academic work was linguistically supported by the Mersin Technology Transfer Office Academic Writing Center of Mersin University

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

The use of fungal biomass agaricus bisporus immobilized on amberlite XAD-4 resin for the solid phase preconcentration of thorium

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−1 HCl. 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

Development of Armillae mellea immobilized nanodiamond for the preconcentrations of Cr(III), Hg(II) and Zn(II)

In this study, we present an environmental friend and easy procedure for simultaneous preconcentration of Cr (III), Hg(II) and Zn(II) by solid-phase extraction before their determination by inductively coupled plasma optical emission spectrometry. Armillae mellea immobilized nanodiamond was used as sorbent. During the study, critical parameters influencing the extraction performance were investigated in detail. The best parameters were found as pH 5.0, 2.0 mL min(-1) of flow rate, 200 mg of Armillae mellea, 300 mL of sample volume. LOD values were found as 0.025, 0.13 and 0.038 ng mL(-1), respectively for Cr(III), Hg(II) and Zn(II). By applying the developed procedure, sensitivities of ICP-OES were improved for 60 fold for Cr(III), Hg(II) and Zn(II). Their concentrations in different food samples were measured after microwave digestion and solid-phase extraction

Preconcentration of Sn in real water samples by solid phase extraction based on the use of helvella leucopus as a fungal biomass prior to its determination by ICP-OES

Recently, biosorbents of biological origin such as fungus, algae, and bacteria have found special application as packing material in solid phase extraction (SPE). In this study, an alternative SPE method was developed and validated for the preconcentration of Sn prior to its determination by inductively coupled plasma optical emission spectrometry (ICPOES). Helvella leucopus, a fungal biomass, was used as the biosorbent in the column studies. Experimental parameters, such as Ph and flow rate of the solution, amounts of biosorbent and resin, and volume of the sample solution which affects the analytical results, were investigated. Effects of possible interfering ions on the SPE preconcentration of Sn were investigated. The sensitivity of ICP-OES was improved 47.1 times for Sn. The LOD and LOQ values were 0.06 and 0.21 ng mL-1, respectively. Linearity was obtained in the concentration range of 1.0–30 ng mL-1 for Sn. The loading capacity of Helvella leucopus immobilized Amberlite XAD-4 was 10.4 g g-1. The concentrations of Sn in the water samples from the Tigris River were determined using the developed method and validated by analysis of the certified reference material NWTM-26.3 Fortified Water sample

DNA cleavage properties and synthesis of metallophthalocyanines with 5-methyl-[1, 2, 4] triazolo [1, 5-a] pyrimidin-7-oxy substituents.

The aim of the present study is to perform synthesis of novel metallophthalocyanines (pcs) with high solubility. The synthesis and characterization of 5-methyl-[1, 2, 4] triazolo [1, 5-a] pyrimidin-7-yloxysubstituted zinc, magnesium, and cobalt pcs are reported. These compounds have been characterized using electronic absorption, nuclear magnetic resonance spectroscopy, infrared, elemental analysis and mass spectra. The aggregation investigations carried out in different concentrations indicate that 5- methyl-[1, 2, 4] triazolo [1, 5-a] pyrimidin-7-yloxy-substituted pc complexes do not have any aggregation behavior for the concentration range of 1 £ 10¡5¡1 £ 10¡6 M in THF. DPPH radical scavenging activity, metal chelating activity, and reducing power of the compounds were evaluated. The DNA gel electrophoresis studies revealed that new phthalonitrile and its metallophthalocyanine compounds cleavaged plasmid DNA (pBR322). Additionally, the ground-state geometries of the complexes were optimized using density functional theory methods at B3LYP/6-31G (d, p) level in order to obtain information about the 3D geometries and electronic structure

Metallo phthalocyanines bearing (2-((2-hydroxyethyl) (p-tolyl)amino)ethoxy) and (2-((2-phenoxyethyl) (p-tolyl)amino)ethoxy) phthalonitrile substituents: Synthesis, characterization, aggregation behavior, antioxidant and antibacterial activity

tThe novel phthalonitrile derivatives bearing (2-((2-hydroxyethyl)(p-tolyl)amino)ethoxy) and (2-((2-phenoxyethyl)(p-tolyl)amino)ethoxy)phthalonitrile substituents at peripheral position were preparedby a nucleophilic displacement reaction. Cyclotetramerization of these phthalonitrile derivatives in thepresence of corresponding metal salts gave the new metallophthalocyanines. The novel compounds werecharacterized by using various spectroscopic data. The aggregation investigations carried out in differ-ent concentrations indicate that phthalocyanine compounds do not have any aggregation behavior forthe concentration range of 10−4–10−6M in tetrahydrofuran. In vitro three antioxidant test methods,namely diphenylpicrylhydrazyl radical scavenging activity, metal chelating activity and reducing powerwere used to determine the antioxidant activity of compounds. Compounds were analyzed for theirantibacterial activity against some bacteria by using the disk-diffusion method

Preconcentrations of Zn(II) and Hg(II) in Environmental and Food Samples by SPE on B. licheniformis Loaded Amberlite XAD-4

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