Using o-pthaldialdehyde (OPT) fluorescence, the amino acids associated with DNA were studied following exposure of intact Chinese hamster ovary cells to chromate. Rigorous extraction with EDTA, acid, or base was required to release the amino acids cross-linked to the DNA isolated from control or chromate-treated cells by standard procedures (i.e., proteinase K, phenol, etc.). Amino acids resist...

Resting cells of Agrobacterium radiobacter EPS-916 grown on glucose, fructose, maltose, lactose, mannitol, or glycerol reduced 0.5 mM chromate. However, resting cells of strain EPS-916 grown on glutamate or succinate did not reduce chromate. The ability of washed cells to reduce chromate was correlated with their redox potential.

Microbial bio-reduction to Cr(III) is a promising strategy for detoxification of chromate, a prevalent anthropogenic pollutant. We propose that this activity can be enhanced in bacteria through engineering of soluble enzymes, such as NfsA, the model Class II chromate reductase of Escherichia coli. We show here that nfsA is induced by chromate, and that it reduces this compound by a “semi-tight”...

The passivation of zinc alloy coating was achieved through the utilization both silicate and trivalent chromium systems, employing a specific process formula consisting Co(NO3)2 at concentration 2.5 g/L, C76H52O46 3 mL/L, Na2SiO3 25 C6H5Na3O7 15 an appropriate amount organic accelerator. composite tannic acid found to be more effective than film, as it successfully eliminated dendrite structure...

Kidney disease is often cited as one of the adverse effects of chromium, yet chronic renal disease due to occupational or environmental exposure to chromium has not yet been reported. Occasional cases of acute tubular necrosis (ATN) following massive absorption of chromate have been described. Chromate-induced ATN has been extensively studied in experimental animals following parenteral adminis...

Chromate [Cr(VI)] is a serious environmental pollutant, which is amenable to bacterial bioremediation. NfsA, the major oxygen-insensitive nitroreductase of Escherichia coli, is a flavoprotein that is able to reduce chromate to less soluble and less toxic Cr(III). We show that this process involves single-electron transfer, giving rise to a flavin semiquinone form of NfsA and Cr(V) as intermedia...

Tandem paired genes encoding putative short-chain monodomain protein members of the chromate ion transporter (CHR) superfamily (ywrB and ywrA) were cloned from genomic DNA of Bacillus subtilis strain 168. The transcription of the paired genes, renamed chr3N and chr3C, respectively, was shown to occur via a bicistronic mRNA generated from a promoter upstream of the chr3N gene. The chr3N and chr3...

OBJECTIVES We aimed to investigate suitable conditions of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and micronucleus (MN) as genotoxic biomarkers at different levels of occupational chromate exposure. DESIGN A cross-sectional study was used. PARTICIPANTS 84 workers who were exposed to chromate for at least 1 year were chosen as the chromate exposed group, while 30 non-exposed individuals were us...

Hexavalent chromium [Cr(VI)] in industrial effluent is one of the most serious environmental problems in India and also in other countries. Micellar-Enhanced Ultrafiltration (MEUF) of the chromate anions from aqueous solutions has been studied at room temperature (28±2°C) using cationic surfactants, cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC), micelles of which adso...

Concentrations of 0.25 and 0.5 mug/ml calcium chromate (CaCrO4-2H2O)dissolved in Dulbecco's medium were found to alter the growth behavior of BHK21 cells in culture. Treated cells grew as shortened fibroblasts and in random orientation. The changes detected during the first two weeks of culture in the presence of the metal became more pronounced as the number of growth passages increased. In ad...