TY - JOUR
T1 - Development and testing of a bacterial biosensor for toluene-based environmental contaminants
AU - Willardson, Barry M.
AU - Wilkins, Jon F.
AU - Rand, Timothy A.
AU - Schupp, James M.
AU - Hill, Karen K.
AU - Keim, Paul
AU - Jackson, Paul J.
PY - 1998/3
Y1 - 1998/3
N2 - 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, P(u). A reporter plasmid was constructed by placing the luc gene for firefly luciferase under the control of XyIR and P(u). 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( 1/4 ) values ranging from 39.0 ± 3.8 μM for 3-xylene to 2,690 ± 160 μM for 3-methylbenzylalcohol (means ± standard deviations). The luminescence response was specific for only toluene-like molecules that bind to and activate XyIR. 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.
AB - 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, P(u). A reporter plasmid was constructed by placing the luc gene for firefly luciferase under the control of XyIR and P(u). 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( 1/4 ) values ranging from 39.0 ± 3.8 μM for 3-xylene to 2,690 ± 160 μM for 3-methylbenzylalcohol (means ± standard deviations). The luminescence response was specific for only toluene-like molecules that bind to and activate XyIR. 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.
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U2 - 10.1128/aem.64.3.1006-1012.1998
DO - 10.1128/aem.64.3.1006-1012.1998
M3 - Article
C2 - 9501440
AN - SCOPUS:0032030612
SN - 0099-2240
VL - 64
SP - 1006
EP - 1012
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
IS - 3
ER -