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Designing A Bacterial Biosensor For Arsenic Detection In Water Solutions
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Maryam Daneshpour   , Nooshin Shabab , Amir Roointan , Alireza Rahmani , Gholam Abbas Chehardoli , Massoud Saidijam * |
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Abstract: (8801 Views) |
| In parallel to continuous development of increasingly more sophisticated physical and chemical
analytical technologies for the detection of environmental pollutants, there's a progressively more urgent
need also for bioassay which report not only on the presence of a chemical but also on its bioavailability
and its biological effects. As a partial fulfillment of that need, there's been a rapid development of
biosensors based on genetically engineered bacteria. Natural water was polluted by arsenic that known
toxin and carcinogen leaded us to designing a whole cell bacterial biosensor to detect arsenic in liquid
solutions.
Methods: In order to construct the biosensor, chromosomal arsR gene and its related promoter/operator
from Escherichia coli strain Bl21(DE3), gfp gene as the reporter, plasmid pUC19 as the basic vector and
different molecular and genetic engineering techniques such as PCR, gene cloning, etc. were applied to
make the Escherichia coli strain BL21(DE3) act as the arsenic whole cell biosensor. Arsenic detection by
using this biosensor was done by means of microscopy and fluorometery techniques. Strain BL21(DE3)
responded mainly to As(III) and As(V) with the lowest detectable concentration being 5 μM during a 3-
hours exposure and 1 and 3 μM respectively, with an 6-hours induction period.
Results: Our result demonstrate that the nonpathogenic bacterial biosensors developed in the present
study could be useful and applicable in determining the bioavailability of arsenic with high sensitivity in
contaminated water samples after further optimization, and they suggest a potential for its inexpensive
application in field-ready tests.
Conclusion: Our success in designing and producing this biosensor, in addition to localizing this useful
technology, will be a very large and effective step to improve the health status of drinking water, through
to speed up detection of arsenic contamination of water resources. It can also attract lots of academic and
industrial heads for research in this interesting field of science and establish an optimistic future in
developing biosensor technology in our country. |
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| Keywords: arsR, Arsenic Contaminant, Biosensor, GFP, Whole Cell Biosensor |
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Full-Text [PDF 925 kb]
(2336 Downloads)
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Type of Study: Research |
Subject:
General
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