title: Regioselective oxidation of xylene isomers by Rhodococcus sp. strain DK17.
abstract: Rhodococcus sp. strain DK17 is able to utilize a variety of monocyclic aromatic hydrocarbons, including benzene, phenol, toluene, and o-xylene, as growth substrates. Although DK17 is unable to grow on m- and p-xylene, this strain could transform these two xylene isomers to some extent after induction by o-xylene. The major accumulating compounds formed during the degradation of m- and p-xylene by DK17 were isolated by high-pressure liquid chromatography and identified by gas chromatography-mass spectrometric and (1)H nuclear magnetic resonance spectral techniques. Both xylene isomers were transformed to dihydroxylated compounds by what must be two successive hydroxylation events: m-xylene was converted to 2,4-dimethylresorcinol and p-xylene was converted to 2,5-dimethylhydroquinone. The rigorous structural identification of 2,4-dimethylresorcinol and 2,5-dimethylhydroquinone demonstrates that DK17 can perform distinct regioselective hydroxylations depending on the position of the substituent groups on the aromatic ring.
authors.affiliation: Department of Biology and Institute of Life Science and Biotechnology, Yonsei University, Seoul 120-749, South Korea.
authors.forename: Dockyu
authors.initials: D
authors.lastname: Kim
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Kim
authors.forename: Jae Woo
authors.initials: JW
authors.lastname: Jung
authors.forename: Gerben J
authors.initials: GJ
authors.lastname: Zylstra
authors.forename: Young Min
authors.initials: YM
authors.lastname: Kim
authors.forename: Seong-Ki
authors.initials: SK
authors.lastname: Kim
authors.forename: Eungbin
authors.initials: E
authors.lastname: Kim
mesh_terms: D006900:Hydroxylation; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000378:metabolism; D012240:Rhodococcus / Q000201:enzymology* / Q000254:growth & development; D013379:Substrate Specificity; D014050:Toluene / Q000737:chemistry / Q000378:metabolism; D014992:Xylenes / Q000737:chemistry / Q000378:metabolism*
chemical_list: D014992:Xylenes; D014050:Toluene; D010105:Oxygenases