• Journal of Plant Biotechnology
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• v.3 no.1
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• pp.13-17
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• 2001

A Chromium (VI)[Cr(VI)] reductase gene from heavy metal reducing bacteria Pseudomonas aeruginosa HP014 was used to transform tobacco plant cells. A chimeric construct containing the Cr(VI) reductase gene was transfered to tobacco leaf disks using an Agrobacteriun tumefaciens binary vector system. From the leaf disks, transformed plantlets were regenerated. Hybridization experiments demonstrated that the Cr(VI) reductase gene was inserted into and expressed in the regenerated plants. The Cr(VI) reduction activity showed that the transgenic plants may be a another possible tool to reduce the pollution of the toxic Cr(VI) in soil.

• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.547-554
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• 2012

Chromium is generated from several industrial processes. It occurs in different oxidation states, but Cr(III) and Cr(VI) are the most common ones. Cr(VI) is a toxic, soluble environmental contaminant. Some bacteria are able to reduce hexavalent chromium to the insoluble and less toxic Cr(III), and thus chromate bioremediation is of considerable interest. An indigenous chromium-reducing bacterial strain, Rb-2, isolated from a tannery water sample, was identified as Ochrobactrum intermedium, on the basis of 16S rRNA gene sequencing. The influence of factors like temperature of incubation, initial concentration of Cr, mobility of bacteria, and different carbon sources were studied to test the ability of the bacterium to reduce Cr(VI) under variable environmental conditions. The ability of the bacterial strain to reduce hexavalent chromium in artificial and industrial sewage water was evaluated. It was observed that the mechanism of resistance to metal was not due to the change in the permeability barrier of the cell membrane, and the enzyme activity was found to be inductive. Intracellular reduction of Cr(VI) was proven by reductase assay using cell-free extract. Scanning electron microscopy revealed chromium precipitates on bacterial cell surfaces, and transmission electron microscopy showed the outer as well as inner distribution of Cr(VI). This bacterial strain can be useful for Cr(VI) detoxification under a wide range of environmental conditions.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.672-675
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• 2000

E.coli ATCC 33456 has relatively higher activity of Cr(VI) reduction than other microorganism. The purpose of this research is cloning of Cr(V) reductase from E.coli ATCC 33456. Using colony and southern hybridization, we selected two condidates. Among candidates, pNCR9 is higher Cr(VI) reduction activity than E.coli ATCC 33456. Purified Cr(VI) reductase antibody was reacted at estimated 42Kda protein band of candidate's crude extract on 12% SDS-PAGE. This results showed cloned gene's product is very similar to purified Cr(VI) reductase from E.coli ATCC 33456.