FEMS Microbiology Letters 1993-06-15

Degradation of meta-trifluoromethylbenzoate by sequential microbial and photochemical treatments.

B F Taylor, J A Amador, H S Levinson

Index: FEMS Microbiol. Lett. 110(2) , 213-6, (1993)

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Abstract

m- and p-trifluoromethyl (TFM)-benzoates are incompletely degraded by aerobic bacteria that catabolize alkylbenzoates; biodegradation ceases after ring-fission with the accumulation of a trifluoromethyl muconate semialdehyde (2-hydroxy-6-oxo-7,7,7-trifluorohepta-2,4-dienoate, TFHOD) which is resistant to biochemical attack. A bacterium (Strain V-1), isolated from sea-water, grew aerobically on benzoate or m-toluate. Cells grown on benzoate or m-toluate oxidized both compounds at similar relative rates. Catabolism involved benzoate 1,2-dioxygenase (decarboxylating) and meta-cleavage to yield muconate semialdehydes. Cells grown on benzoate metabolized m-TFM-benzoate to TFHOD. The ring-fission products from m-toluate and TFHOD were degraded by sunlight, and equimolar fluoride was released from TFHOD. Sequential biochemical and photochemical treatment allowed the destruction of m-TFM-benzoate beyond the biochemically recalcitrant intermediate TFHOD.