Structural and Genetic Diversity of Hexavalent Chromium-Resistant
Culture-independent and -dependent methods were used to evaluate the genetic diversity of hexavalent chromium-resistant bacteria in contaminated soils. Denaturing gradient gel electrophoresis (DGGE) showed that hexavalent chromium-resistant bacteria in contaminated soils had significant structural diversity that was not …
Chromium
Chromium is a steel gray, lustrous, hard metal extracted from chromite ores. In 2011, U.S. production of chromium was estimated at 160,000 metric tons, coming almost entirely from recycling stainless steel scraps. In addition, the U.S. imported 430,000 metric tons of chromium, primarily from South Africa, Kazakhstan, Russia and China. Chromium is …
Hexavalent Chromium | NIOSH | CDC
CAS No. 1. Hexavalent chromium (Cr (VI)) compounds are a large group of chemicals with varying properties, uses, and workplace exposures. Hexavalent chromium is harmful to the eyes, skin, and respiratory system. NIOSH considers all Cr (VI) compounds to be occupational carcinogens. Workers may be harmed from exposure to hexavalent …
Microbiological reduction of hexavalent chromium by …
Indigenous bacteria that are resistant to high concentrations of Cr(VI) were isolated from a Cr-contaminated sediment. ... Microbiological reduction of hexavalent chromium by indigenous chromium-resistant bacteria in sand column experiments Environ Geochem Health. 2008 Apr;30(2):141-5. doi: 10.1007/s10653-008-9132-6.
Structural and Genetic Diversity of Hexavalent …
Hexavalent chromium-resistant bacteria were isolated from sample D in the Hunan province, and their genetic diversity was analyzed. For bacterial isolation, 10 g of soil was added into 10 mL of ...
Reduction of Hexavalent Chromium by Viable Cells of Chromium Resistant …
Chromium resistant and reducing bacteria, belonging to Arthrobacter, Pseudomonas, and Corynebacterium isolated from chromite mine overburden and seepage samples of Orissa, India, were found to tolerate 12–18 mM Cr(VI) during growth. Environmental contamination of hexavalent chromium [Cr(VI)] is of serious concern for …
Hexavalent chromium removal by a resistant strain Bacillus …
The chromium-resistant Bacillus aryabhattai CTSI-07 (MG757377) showed resistance to 1000 and 300 ppm of Cr(VI) in nutrient rich Luria Bertani (LB) and nutrient-deficient sucrose low phosphate (SLP) medium, respectively, and can be used for long-term reclamation of chromium-contaminated soil to restore soil health, provide food safety, …
(PDF) Mechanisms of Hexavalent Chromium …
Hexavalent chromium is used extensively in industrial processes such as electroplating, tanning, textile dyeing, corrosion inhibition and wood treatment, all of which produce discharge of...
Bioremediation of Hexavalent Chromium by Chromium Resistant …
Chromium (Cr) (VI) has long been known as an environmental hazard that can be reduced from aqueous solutions through bioremediation by living cells. In this study, we investigated the efficiency of reduction and biosorption of Cr (VI) by chromate resistant bacteria isolated from tannery effluent. From 28 screened Cr (VI) resistant isolates ...
Alternatives to Using Hexavalent Chromium Coatings – …
This proved that hexavalent chromium coating has a better corrosion resistance than molybdate, tungstate, and vanadate coatings. 4.5 Trivalent Chromium Coatings. Trivalent chromium conversion coating has been used most prevalently as a replacement for hexavalent chromium systems since being developed for zinc metal …
Hexavalent chromium-resistant bacteria isolated from …
Hexavalent chromium [Cr(VI)] is a known carcinogen and mutagen; however, the actual mechanisms of Cr toxicity are unknown. Two approaches were used to isolate Cr(VI)-resistant bacteria from metal ...
Bioremediation of Hexavalent Chromium by Chromium Resistant …
Chromium (Cr) (VI) has long been known as an environmental hazard that can be reduced from aqueous solutions through bioremediation by living cells. In this study, we investigated the efficiency of reduction and biosorption of Cr(VI) by chromate resistant bacteria isolated from tannery effluent. From 28 screened Cr(VI) resistant isolates, …
Hexavalent chromium removal in vitro and from industrial …
Two chromate-resistant filamentous fungi, strains H13 and Ed8, were selected from seven independent fungal isolates indigenous to Cr(VI)-contaminated soil because of their ability to decrease hexavalent chromium levels in the growth medium. Morphophysiological studies identified strain H13 as a Peni …
HEXAVALENT CHROMIUM REDUCTION POTENTIAL OF CHROMIUM RESISTANT …
Seventeen bacterial isolates from tannery effluent was tested for their ability to resist chromium (Cr) and reduce hexavalent chromium (Cr (VI)). Reduction study was carried out by individual isolates and also by their consortia. All the isolates could resist 25 mg L-1 chromium. Some isolate was found to resist >90 mg L-1 chromium.
Development of high concentration hexavalent chromium resistant strain
The tolerance data with a high range of heavy metal concentrations revealed the Cr-resistant isolates, especially the fungal one, could tolerate chromium toxicity at up to 10,000 mg L(-1) chromium.
Health hazards of hexavalent chromium (Cr (VI)) and its …
There is not a thorough investigation on the use of chromium-resistant bacteria to remediate chrome-polluted effluent. Hexavalent chromium is a well-known environmental contaminant that has the potential to cause cancer, teratogenicity, and mutation . The goal of this review is to reveal the harmful effects of Cr (VI), as well as …
Toxicity of Hexavalent Chromium: Review
Hexavalent chromium is less stable than trivalent chromium. Among trivalent (Cr (III)) and hexavalent (Cr (VI)) chromium has completely different toxicity and …
Mechanisms of hexavalent chromium resistance and …
There are several Cr-resistance mechanisms that are displayed by microorganisms. These include active efflux of Cr compounds, metabolic reduction of Cr (VI) to Cr (ill), and either intercellular or extracellular prec1p1tation. Microbial Cr (VI) removal typically involves three stages: binding of chromium to the cell surface, translocation of ...
(PDF) Bioreduction of hexavalent chromium by …
Both the strains were found to achieve highest chromium (VI) bioreduction of 94 and 95% in 100 mg/L at the end of 25 h at pH 9.0. At an optimized concentration of …
(PDF) Study on Hexavalent Chromium Reduction by Chromium Resistant
Therefore, Acinetobacter calcoaceticus may be use in the bioremediation of hexavalent chromium toxicity.DOI: 10.3126/on.v8i1.4313 Hexavalent chromium reduction (24 hr) of bacterial isolates in LB.
Bioreduction of hexavalent chromium by chromium resistant …
1. Introduction. Hexavalent chromium Cr(VI) is one of the major environmental pollutant discharged from various industrial effluents, such as, pigment, paint, textile dyes, leather tanning, metal processing and electroplating industries, etc. (Adki et al., 2013; Dhandapani et al., 2020).Among all, tannery industries are considered to be the …
The Role of Chromium in Stainless Steel: Corrosion Resistance …
At room temperature, chromium exists in two common forms: hexavalent chromium (Cr6+) and trivalent chromium (Cr3+). Both forms are essential for various processes in our bodies and the environment. ... Stainless steel is an alloy that contains at least 10.5% chromium, making it resistant to corrosion and staining. It also has high …
Mechanisms of hexavalent chromium resistance and …
There are several Cr-resistance mechanisms that are displayed by microorganisms. These include active efflux of Cr compounds, metabolic reduction of Cr (VI) to Cr (ill), and …
Hexavalent chromium removal by a resistant strain
It grew normally in the media containing 10-100 mg/L Cr(VI), indicating its high resistance to Cr(VI). Under the optimal conditions of pH 7.0, inoculation amount 10%, and …
Chromate Reductase YieF from Escherichia coli …
Hexavalent chromium (Cr(VI)) is a serious environmental pollutant and human toxicant. Mammalian cells are very sensitive to chromate as they lack efficient chromate detoxifying strategy, e.g., …
Full article: Hexavalent chromium reduction by chromate-resistant …
Environmental contamination by hexavalent chromium, Cr(VI), presents a serious public health problem. Enrichment led to the isolation of 12 bacteria displaying different degrees of chromate reduction. ... Zhang K, Li F. Isolation and characterization of a chromium-resistant bacterium Serratia sp. Cr-10 from a chromate-contaminated site.
Hexavalent chromium, a lung carcinogen, confers resistance …
Exposure to hexavalent chromium [Cr(VI)], a lung carcinogen, triggers several types of cellular stresses, namely oxidative, genotoxic and proteotoxic stresses. Given the evolutionary character of carcinogenesis, it is tempting to speculate that cells that survive the stresses produced by this carcinogen become more resistant to subsequent ...
Bioremediation of Hexavalent Chromium by Chromium Resistant …
Chromium. chromium hexavalent ion. Chromium (Cr) (VI) has long been known as an environmental hazard that can be reduced from aqueous solutions through bioremediation by living cells. In this study, we investigated the efficiency of reduction and biosorption of Cr (VI) by chromate resistant bacteria isolated from tannery effluent. Fro ….
Hexavalent Chromium | NIOSH | CDC
- NIOSH Criteria Document: Criteria for a Recommendation Standard for an Occupational Exposure to Hexavalent Chromium– DHHS (NIOSH) Publication No. 2013-128 (2013). This report increases awareness an...
- NIOSH Criteria Document: Criteria for a Recommended Standard: Welding, Brazing, and Thermal Cutting– DHHS (NIOSH) Publication No. 88-110 (1988). Welders are at an increase…
- NIOSH Criteria Document: Criteria for a Recommendation Standard for an Occupational Exposure to Hexavalent Chromium– DHHS (NIOSH) Publication No. 2013-128 (2013). This report increases awareness an...
- NIOSH Criteria Document: Criteria for a Recommended Standard: Welding, Brazing, and Thermal Cutting– DHHS (NIOSH) Publication No. 88-110 (1988). Welders are at an increased risk for lung cancer, a...
- NIOSH Comments on the Occupational Safety and Health Administration (OSHA) Request for Information on Occupational Exposure to Hexavalent Chromium
- NIOSH Docket 144: Hexavalent Chromium Criteria Document
Bioreduction of hexavalent chromium by chromium resistant …
The results showed that the isolate could be applied as a potential bioremediation agent for Cr6+ removal and the residual chromium was found in the form of less toxic trivalent chromium (Cr3+), which confirms that the bacterial isolate can transform toxic Cr 6+ to non-toxic Cr3+.
