Chromium and chromium containing compounds are discharged into the nature as waste from anthropogenic activities, such as industries, agriculture, forest farming, mining and metallurgy. Continued disposal of these compounds to the environment leads to development of various lethal diseases in both humans and animals. In this paper, we report a soil borne bacterium, B2-DHA that can be used as a vehicle to effectively remove chromium from the contaminated sources. B2-DHA is resistant to chromium with a MIC value of 1000 µg mL(-1) potassium chromate. The bacterium has been identified as a Gram negative, Enterobacter cloacae based on biochemical characteristics and 16S rRNA gene analysis. TOF-SIMS and ICP-MS analyses confirmed intracellular accumulation of chromium and thus its removal from the contaminated liquid medium. Chromium accumulation in cells was 320 µg/g of cells dry biomass after 120-h exposure, and thus it reduced the chromium concentration in the liquid medium by as much as 81%. Environmental scanning electron micrograph revealed the effect of metals on cellular morphology of the isolates. Altogether, our results indicate that B2-DHA has the potential to reduce chromium significantly to safe levels from the contaminated environments and suggest the potential use of this bacterium in reducing human exposure to chromium, hence avoiding poisoning.
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http://dx.doi.org/10.1080/10934529.2015.1047670 | DOI Listing |
Imaging Sci Dent
December 2024
Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
Purpose: This study was performed to evaluate the expression of beam hardening artifacts generated by high atomic number materials in stitched cone-beam computed tomography (CBCT) images, compared to the traditional acquisition mode.
Materials And Methods: CBCT volumes were acquired using an acrylic resin phantom embedded with pairs of cylinders made from amalgam dental alloy, cobalt-chromium alloy, gutta-percha, titanium, and zirconium. These cylinders were placed within the overlapping zones of the stitching reconstruction area.
Int J Biol Macromol
December 2024
School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China. Electronic address:
In this paper, Mg/Al-layered double hydroxide (Mg/Al-LDH) was modified with the natural polymers sodium alginate and guar gum, and the prepared GG/SA/Mg-Al-LDH composite microsphere adsorbent (G-LDH) showed better adsorption performance for Congo red and hexavalent chromium in aqueous solution than the Mg/Al-LDH. The adsorption and surface properties of G-LDH in terms of functional groups, basic constituent elements and structural properties were obtained by different techniques. SEM shows that the average particle size of G-LDH is between 400 and 900 nm and exhibits a distinct microsphere morphology.
View Article and Find Full Text PDFEcotoxicol Environ Saf
December 2024
Chinese Academy of Geological Sciences, China Geology Survey, Ministry of Natural Resources, Beijing 100037, China.
This study investigates the pollution characteristics, spatial patterns, causes, and ecological risks of heavy metals in the soils of the southeastern Hubei polymetallic mining areas, specifically the Jilongshan (JLS) and Tonglushan (TLS) regions, located in the middle and lower reaches of the Yangtze River. The main findings are as follows: (1) Among the heavy metals present in the soil, copper (Cu) has the highest average concentration at 278.54 mg/kg, followed by zinc (Zn) at 161.
View Article and Find Full Text PDFJ Prosthet Dent
December 2024
Associate Professor, Dental Biomaterials Research Laboratory, Department of Restorative Dentistry, Gerald Niznick College of Dentistry, University of Manitoba, Winnipeg, Manitoba, Canada. Electronic address:
Statement Of Problem: The mechanical properties and microstructure of cobalt chromium (Co-Cr) alloys should be considered when choosing the best alloy for each clinical situation. More information is needed on the digital manufacturing methods of metals in dentistry, such as computer numerical control (CNC), and direct laser metal sintering (DMLS).
Purpose: The aim of this study was to investigate the effect of the 3 different Co-Cr manufacturing processes on the mechanical properties and microstructure of Co-Cr dental alloys.
J Hazard Mater
December 2024
School of Environment and Resource, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China; Key Laboratory of Solid Waste Treatment and Resource Recycle, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China. Electronic address:
Chromium [Cr(VI)]-induced soil pollution is a serious environmental threat. Bioremediation utilizes specific microbes capable of transforming Cr(VI) into the less toxic Cr(III), however, microbial efficacy can be inhibited by elevated pollutant concentrations and competition from indigenous microbial communities. Thus, this study explored the potential of single and multi-domain microbial consortia encapsulated in alginate to overcome these shortcomings.
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