title: Regulation of chloro- and methylphenol degradation in Comamonas testosteroni JH5.
abstract: Comamonas testosteroni JH5 was isolated from a mixed bacterial culture enriched on different chloro- and methylphenols. The strain completely mineralized a mixture consisting of 4-chlorophenol (4-CP) and 4-methylphenol (4-MP). During degradation of the mixture, 4-hydroxybenzyl alcohol, 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid, and 4-chlorocatechol were detected as short-lived intermediates. Mineralization of 4-CP and that of 4-MP occurred successively and were accompanied by diauxic growth, whereas 4-CP and 2-methylphenol were mineralized simultaneously. It was ascertained that neither a reversible enzyme inhibition nor potential toxic intermediates caused the observed diauxie. Some facts support the hypothesis that the successive degradation of 4-CP and 4-MP is regulated on the level of transcription. C. testosteroni JH5 contained a meta-cleaving enzyme when pregrown on 4-CP and the isomeric monomethylphenols. Inactivation of this enzyme in the presence of 3-chlorocatechol was observed.
authors.affiliation: Fachgebiet Hygiene, Technische Universität Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Hollender
authors.forename: W
authors.initials: W
authors.lastname: Dott
authors.forename: J
authors.initials: J
authors.lastname: Hopp
mesh_terms: D001673:Biodegradation, Environmental; D050557:Catechol 2,3-Dioxygenase; D002733:Chlorophenols / Q000378:metabolism*; D003408:Cresols / Q000378:metabolism*; D049308:Dioxygenases; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010101:Oxygen Consumption; D010105:Oxygenases / Q000037:antagonists & inhibitors; D010226:Parabens / Q000378:metabolism; D011549:Pseudomonas / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D002733:Chlorophenols; D003408:Cresols; D010226:Parabens; C032538:4-cresol; C029107:4-chlorophenol; D010105:Oxygenases; D049308:Dioxygenases; D050557:Catechol 2,3-Dioxygenase; C038193:4-hydroxybenzoic acid; C034047:2-cresol