Research Product

Pseudomonas sp. N.C.I.B. 9816, strain 11, when grown on salicylate in the presence of dibenzo-p-dioxin, accumulated cis-1,2-dihydroxy-1,2-dihydrodibenzo-p-dioxin and 2-hydroxydibenzo-p-dioxin in the culture medium. Crude cell extracts prepared from the parental strain grown with naphthalene oxidized cis-1,2-dixhydroxy-1,2-dihydrodibenzo-p-dioxin to 1,2-dihydroxydibenzo-p-dioxin.Further degradation of the metabolite was not detected. Whole cells of the parent strain of Beijerinckia, grown with succinate and biphenyl, oxidized dibenzo-p-dioxin and several chlorinated dioxins. 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 four hours when 0.05% Dibenzo-p-dioxin was present in the culture medium. Resting cell suspensions of the parent organism 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.