Mutant microbes could work for EPA.
The scientists work with bacteria that metabolize simple phenols. Related phenol molecules, used in dyes, pesticides, photographic chemicals, and elsewhere, can make their way into the water supply and pollute it. The Environmental Protection Agency lists 11 phenols among its priority pollutants, notes Wise.
Normally, phenol-eating bacteria ingest the molecules, which then attach to a receptor called DmpR. That complex then binds to DNA and activates metabolic genes. Wise and her colleagues manipulated this pathway by mutating the gene for DmpR and adding to the bacteria a reporter gene that any DmpR-phenol complex could activate. The mutations allow the bacteria to metabolize more complex phenols, including many of the ones listed by EPA. When the bacteria encounter phenols, they turn on the reporter gene, which produces an easily detected protein, says Wise.
The phenol biosensors; aren't perfect yet, however. While some strains are extremely sensitive to phenols, they can't distinguish toxic and nontoxic varieties. Other strains are more finicky but less sensitive. "I have a lot of mutant strains in the freezer that I haven't tested yet," says Wise.
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|Title Annotation:||mutated bacteria could be use as phenol monitors|
|Article Type:||Brief Article|
|Date:||Jun 13, 1998|
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