Formation of 2,4-Dichlorophenol and 2,4-Dichloroanisole From 2,4-Dichlorophenoxyacetate by Arthrobacter Sp.

Low concentrations of a phenolic metabolite accumulated in the medium during the early stages of growth of an Arthrobacter sp. in a medium containing 2,4-dichlorophenoxyacetate (2,4-D). The metabolite was identified by gas chromatography, ultraviolet and infrared absorption analysis, and paper chromatography of a nitro-derivative as 2,4-dichlorophenol, thus providing direct evidence that 2,4-D was degraded by the bacterium via its corresponding phenol. A second metabolite, identified by its retention time in the gas chromatograph and its reaction with HI as 2,4-dichloroanisole, was also produced. However, 2,4-D-grown cells, which converted 4-hydroxyphenoxyacetate to hydroquinone, failed to produce hydroquinone during the metabolism of 4-hydroxyanisole, suggesting that the conversion of phenoxyacetates to their corresponding phenols by the bacterium did not proceed via the corresponding anisoles. The role of 2,4-dichloroanisole in the metabolism of 2,4-D by this organism remains unknown.