Willardson, Barry M. and Wilkins, Jon F. and Rand, Timothy A. and Schupp, James M. and Hill, Karen K. and Keim, Paul and Jackson, Paul J. (1998) Development and testing of a bacterial biosensor for toluene-based environmental contaminants. Applied and Environmental Microbiology, 64 (3). pp. 1006-1012. ISSN 1098-5336
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Abstract
A bacterial biosensor for benzene, toluene, and similar compounds has been constructed, characterized, and field tested on contaminated water and soil. The biosensor is based on a plasmid incorporating the transcriptional activator xylR from the TOL plasmid of Pseudomonas putida mt-2. The XylR protein binds a subset of toluene-like compounds and activates transcription at its promoter, Pu. A reporter plasmid was constructed by placing the luc gene for firefly luciferase under the control of XylR and Pu. When Escherichia coli cells were transformed with this plasmid vector, luminescence from the cells was induced in the presence of benzene, toluene, xylenes, and similar molecules. Accurate concentration dependencies of luminescence were obtained and exhibited K 1/2 values ranging from 39.0 3.8 M for 3-xylene to 2,690 160 M for 3-methylbenzylalcohol (means standard deviations). The luminescence response was specific for only toluene-like molecules that bind to and activate XylR. The biosensor cells were field tested on deep aquifer water, for which contaminant levels were known, and were able to accurately detect toluene derivative contamination in this water. The biosensor cells were also shown to detect BETX (benzene, toluene, and xylene) contamination in soil samples. These results demonstrate the capability of such a bacterial biosensor to accurately measure environmental contaminants and suggest a potential for its inexpensive application in field-ready assays.
| Item Type: | Article |
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| Keywords: | Alcohols; aromatic-hydrocarbons; bacteria; benzene; Biosensors; contamination; Enzymes; gene-product; Genes; luminescence; nucleotide-sequence; pseudomonas-putida; soils; tol plasmid; Toluene; transcription initiation site; upper pathway; upstream regulatory sequence; water; Xylene; xylene metabolism; xylr |
| Subjects: | Q Science > QR Microbiology |
| NAU Depositing Author Academic Status: | Faculty/Staff |
| Department/Unit: | College of Engineering, Forestry, and Natural Science > Biological Sciences |
| Date Deposited: | 30 Sep 2015 16:24 |
| URI: | http://openknowledge.nau.edu/id/eprint/352 |
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