Bioreduction of Hexavalent Chromium from Soil Column Leachate by Pseudomonas stutzeri |
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Authors: | Deepika Kumari Daoyong Zhang Chenxi Zhao Fahad A Al-Misned M Golam Mortuza |
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Institution: | 1. Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China;2. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China;3. Xinjiang Academy of Environmental Protection Sciences, Urumqi, China;4. Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia;5. Department of Zoology, Faculty of Life and Earth Science, Rajshahi University, Rajshahi, Bangladesh |
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Abstract: | Bioreduction of Cr(VI) to less toxic Cr(III) by chromate-reducing bacteria has offered an ecological and economical option for chromate detoxification. The present study reports isolation of chromate-resistant bacterial strain Cr8 from chromium slag, identified as Pseudomonas stutzeri, based on 16S rRNA gene sequencing and their potential use in Cr(VI) reduction. The reduced product associated with bacterial cell was characterized by scanning electron microscopy–energy-dispersive x-ray spectroscopy (SEM-EDS) and x-ray diffraction (XRD) analyses. At initial concentrations of 100 and 200 mg L?1 Cr(VI), P. stutzeri Cr8 reduced Cr(VI) completely within 24 h, whereas it reduced almost 1000 mg L?1 Cr(VI) at the end of 120 h. Further, soil column leaching experiments were performed and found that bacterial cells reduced Cr(VI) leachate at faster rate that almost disappeared at the end of 168 h. The leachate precipitates also revealed efficient chromate bioreduction. The remediation process utilizing P. stutzeri could be considered as a viable alternative to reduce Cr(VI) contamination, especially emanating from the overburden dumps of chromite ores and mine drainage. |
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Keywords: | bioremediation Cr(III) mineral chromate leachate Pseudomonas stutzeri |
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