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GENOTOXICITY OF 2,4,5-TRICHLOROPHENOXYACETIC ACID BIODEGRADATION PRODUCTS IN THE SALMONELLA REVERSION AND LAMBDA PROPHAGE-INDUCTION BIOASSAYS
Citation:
George, S., D. White, AND L. Claxton. GENOTOXICITY OF 2,4,5-TRICHLOROPHENOXYACETIC ACID BIODEGRADATION PRODUCTS IN THE SALMONELLA REVERSION AND LAMBDA PROPHAGE-INDUCTION BIOASSAYS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-92/372 (NTIS PB93107175), 1992.
Description:
The herbicide, 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), is still an environmental hazard because of its persistent nature even though its use was outlawed in this country in the 1960's. n order to eliminate the contamination created by 2,4,5-T application, storage, and disposal, several options are available, including bioremediation. herefore it must be determined if the contaminant and its genotoxicity are reduced during this process. seudomonas cepacia strain Ac1100 has been isolated and reported to utilize 2,4,5-T as sole carbon and energy source. etabolites from the 2,4,5-T degradation pathway were tested for their mutagenicity in the Salmonella reversion bioassay and genotoxicity in the prophage-induction bioassay. he parental compound and 3 reported metabolites were negative with and without metabolic activation in S. typhimurium strains TA98, TA100, TA102, and TA104. onversely, 2,4,5-T and 2,4,5-TCP were positive in the prophage-induction bioassay with added S9. ,4,5-TCP was approximately 100 fold more genotoxic than 2,4,5-T. ,5-Dichlorohydroquinone was a weak direct acting genotoxicant in this assay. n order to determine if strain AC1100 eliminated genotoxicity, 2,4,5-T medium was inoculated and the genotoxicity and the amount of 2,4,5-T remaining were examined over the growth period. s cell numbers increased, the percent 2,4,5-T remaining decreased. his decrease coincinded with a decrease in genotoxicity in the prophage-induction bioassay. o mutagenic response was observed in the Salmonella reversion assay. hese results would encourage the use of bioremediation for 2,4,5-T, however the process should be monitored for 2,4,5-TCP.