title: Biotransformation of 1,2,3-tri- and 1,2,3,4,7,8-hexachlorodibenzo-p- dioxin by Sphingomonas wittichii strain RW1.
abstract: Sphingomonas wittichii RW1 is able to catabolize 1,2,3,4-tetrachlorodibenzo-p-dioxin (H. B. Hong, Y. S. Chang, I. H. Nam, P. Fortnagel, and S. Schmidt, Appl. Environ. Microbiol. 68:2584-2588, 2002). Here we demonstrate the aerobic bacterial catabolism of the ubiquitous toxic diaryl ether pollutant 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin by this strain. The products of this biotransformation were identified as tetrachlorocatechol and 2-methoxy-3,4,5,6-tetrachlorophenol by comparing mass spectra recorded before and after n-butylboronate and N,O-bis(trimethylsilyl)-trifluoroacetamide derivatization with those of authentic compounds. Additional experiments showed that the less-chlorinated 1,2,3,7,8-pentachlorodibenzo-p-dioxin was not transformed by the strain RW1. The importance of substitution patterns for the degradability of individual congeners was illustrated by the fact that the 1,2,3-trichlorodibenzo-p-dioxin was catabolized to yield 3,4,5-trichlorocatechol, whereas the 2,3,7-trichlorodibenzo-p-dioxin was not attacked.
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea.
authors.forename: In-Hyun
authors.initials: IH
authors.lastname: Nam
authors.forename: Young-Mo
authors.initials: YM
authors.lastname: Kim
authors.forename: Stefan
authors.initials: S
authors.lastname: Schmidt
authors.forename: Yoon-Seok
authors.initials: YS
authors.lastname: Chang
mesh_terms: D001711:Biotransformation; D002396:Catechols / Q000737:chemistry / Q000378:metabolism; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000378:metabolism*; D020578:Sphingomonas / Q000378:metabolism*
chemical_list: D002396:Catechols; D000072317:Polychlorinated Dibenzodioxins; C018073:hexachlorodibenzo-4-dioxin