Oxidative stress,glutathione level and antioxidant response to heavy metals in multi-resistant pathogen,Candida tropicalis

In this study, we explored the multiple heavy metal-resistant yeast isolated from heavy metal-polluted environment. The isolated yeast showed maximum growth at 30 °C, pH 7.0, and the strain was identified as Candida tropicalis through 18S ribosomal RNA (rRNA) gene sequence analysis. Yeast cells grew well in medium containing different concentrations of heavy metal ions [CdCl₂, Pb(NO₃)₂, NaAsO₂, CuSO₄ and K₂Cr₂O₇]. Minimum inhibitory concentration (MIC) against different metal ions was ranged from 5 to 19 mM, and the metal resistance value against each metal observed by yeast cells was 5 mM (Cr), 10 mM (Cd), 15 mM (As), 14 mM (Cu) and 19 mM (Pb) and increased in the following order: Pb > Cu > As ≥ Cd > Cr. The total cellular glutathione, GSH/GSSG redox couple and metallothioneins like protein (MT) were assayed by growing cultures for 24 h and exposed to 100 mg/L of each heavy metal ion. Remarkable increase in γ-glutamylcysteinylglycine (GSH) level was determined in arsenic and cadmium treatment followed by chromium, lead and copper. Stressed cells had much more oxidized GSH than unstressed cells. GSH/GSSG ratio was significantly increased in cadmium and copper treatment in contrast to chromium, arsenic and lead. Statistical analysis revealed significantly higher cysteine level in all metal-treated samples as compared to control. Antioxidant glutathione transferase activity was not detected in metal-treated and untreated yeast samples. One-dimensional electrophoresis of proteins revealed marked differences in banding pattern of heavy metal-exposed yeast samples. A prominent 20 kDa band was observed in all treated samples suggesting that some differential proteins could be over-expressed during heavy metal treatment and might be involved in cell resistance mechanisms.     

Highly efficient degradation of metronidazole drug using CaFe2O4/PNA nanohybrids as metal-organic catalysts under microwave irradiation

Environmental Science and Pollution Research - Catalytic degradation based on microwave irradiation is an emerging technique which promises prompt and efficient catalytic degradation of organic...     

Determination of sources of fine particles in different ambient atmospheres in South Korea using a chemical mass balance model

Abstract

To determine the sources of particulate matter less than 2.5?μm (PM_2.5 in different ambient atmospheres (urban, roadside, industrial, and rural sites), the chemical components of PM_2.5 such as ions (Cl^-, NO₃^-, SO₄^2-, NH₄⁺, Na⁺, K⁺, Ca²⁺, and Mg²⁺), carbonaceous species, and elements (Al, As, Ba, Cd, Cu, Fe, Mn, Ni, Pb, Se, V, and Zn) were measured. The average mass concentrations of PM_2.5 at the urban, roadside, industrial, and rural sites were 31.5?±?14.8, 31.6?±?22.3, 31.4?±?16.0, and 25.8?±?12.4?μg/m³, respectively. Except for secondary ammonium sulfate and ammonium nitrate, the model results showed that the traffic source (i.e., the sum of gasoline and diesel vehicle sources) was the most dominant source of PM_2.5 (17.1%) followed by biomass burning (13.8%) at the urban site. The major primary sources of PM_2.5 were consistent with the site characteristics (diesel vehicle source at the roadside site, coal-fired plants at the industrial site, and biomass burning at the rural site). Seasonal data from the urban site suggested that ammonium sulfate and ammonium nitrate were the most dominant sources of PM_2.5 during all seasons. Further, the contribution of road dust source to PM_2.5 increased during spring and fall seasons. We conclude that the determination of the major PM_2.5 sources is useful for establishing efficient control strategies for PM_2.5 in different regions and seasons.     

In vitro evaluation of the effect of dibutyl phthalate on electrogenic sodium-linked glucose transport in isolated rabbit ileum

Dibutyl phthalate, a known endocrine disruptor, is a commonly used plasticizer that influences the glucose homeostasis. The present study elucidates the effects of dibutyl phthalate (1 and 5 mmol/L) on electrogenic sodium-linked glucose transport in the isolated rabbit ileum with ‘Ussing chamber.’ Serosal addition of dibutyl phthalate has no effect on glucose-based electrogenic changes in short circuit current, and no effect of dibutyl phthalate is observed on ileal tissue conductance and catalase activity. However, mucosal addition of dibutyl phthalate in the presence of glucose shows a trend of decrease in short circuit current compared with the control. This indicates that dibutyl phthalate may have a deleterious effect on the electrogenic intestinal glucose transport.     

Air pollution and hospitalization in megacities: empirical evidence from Pakistan

Environmental Science and Pollution Research - Air pollution has become a threat to human health in urban settlements, ultimately leading to negative impacts on overall economic system as well....     

Air pollution and child health: the impact of brick kiln pollution on children's cognitive abilities and physical health in Pakistan

Environment, Development and Sustainability - This study explores the adverse impact of air pollution, caused by emissions from brick kilns, on the children’s cognitive ability and physical...     

Synthesis of BiVO4/TiO2 composites and evaluation of their photocatalytic activity under indoor illumination

BiVO₄/TiO₂ composites with different weight ratios have been prepared by coprecipitation-based reactions followed by either thermal or hydrothermal treatment with the aim of evaluating the TiO₂ photosensitization by BiVO₄. The obtained materials present in all cases the desired monoclinic phase of BiVO₄ and anatase phase of TiO₂. Visible light absorption increased with increasing amount of bismuth vanadate. XPS results reveal the surface enrichment of Ti with respect to the bulk composition in samples characterised by a higher content of BiVO₄. The photocatalytic activity of the prepared materials was tested for the degradation of isopropanol in the gas phase under indoor illumination conditions. Although none of the composites was able to improve the activity of TiO₂, the low BiVO₄ containing samples appear as more suitable for further synthesis tuning.     

Pb-induced changes in roots of two cultivated rice cultivars grown in lead-contaminated soil mediated by smoke

Environmental Science and Pollution Research - Nowadays, public concerns regarding deleterious effect of lead (Pb) is on rise due to its abundance and toxic effect on plants and other living...     

Adsorption of Cr(VI) by NaOH-modified microporous activated carbons derived from the wastes of Amaranthus retroflexus,Magnolia soulangeana,and Tanacetum Vulgar L.: mechanism,isotherms, and kinetic studies

Environmental Science and Pollution Research - The study was designed to synthesize microporous activated carbons from the wastes of three medicinal herbs by NaOH as an activator followed by...     

Sustainable application of cochineal-based anthraquinone dye for the coloration of bio-mordanted silk fabric

Natural colors particularly animal-based colorants are employed in the field of cosmetics, food, and flavors and also gaining popularity in textiles, due to their soothing nature. In this study, the microwave-assisted extraction of colorant from cochineal insects for dyeing of bio-mordanted silk has been carried out. Acidic, methanolic, and acidified methanol solubilized media were used to extract the natural colorant from cochineal under microwave irradiation for 1–6 min. Bio-mordants have been employed at optimized conditions to make the process greener and sustainable. It is found that acid solubilized extract of pH 4, employed at 55 °C for 55 min containing 5 g/100 mL of Glauber’s salt as exhausting agent has given high color strength onto microwave-treated silk fabric. Suggested ISO standards for colorfastness have revealed that bio-mordants have given excellent color depth and excellent rating of fastness properties, compared with chemical mordants used. It is found that microwave treatment has not only improved the dyeing behavior of colorant extracted from cochineal in acid solubilized medium but also enhanced the color characteristics onto bio-mordanted silk fabric.