title: Metabolism of Dibenzo-p-Dioxin and Chlorinated Dibenzo-p- Dioxins by a Beijerinckia Species.
abstract: Whole cells of the parent strain of Beijerinckia, grown with succinate and biphenyl, oxidized dibenzo-p-dioxin and several chlorinated dioxins. The rate of oxidation of the chlorinated dibenzo-p-dioxins decreased with an increasing degree of chlorine substitution. A mutant strain (B8/36) of Beijerinckia oxidized dibenzo-p-dioxin to cis-1,2-dihydroxy-1,2-dihydrodibenzo-p-dioxin. The mutant organism also oxidized two monochlorinated dibenzo-p-dioxins to cis-dihydrodiols. No metabolites were detected from two dichlorinated dibenzo-p-dioxins. Growth of the parent strain of Beijerinckia on succinate was inhibited after 4 h when 0.05% dibenzo-p-dioxin was present in the culture medium. Resting cell suspensions of the parent organism, previously grown with succinate and biphenyl, oxidized dibenzo-p-dioxin to a compound identified as 1,2-dihydroxydibenzo-p-dioxin. Further degradation of this metabolite was not detected, as the compound was found to be a potent mixed-type inhibitor of two ring-fission oxygenases present in this organism.
authors.affiliation: Department of Microbiology, The University of Texas at Austin, Austin, Texas 78712.
authors.forename: G M
authors.initials: GM
authors.lastname: Klecka
authors.forename: D T
authors.initials: DT
authors.lastname: Gibson