Identification and characterization of a Pseudomonas strain capable of metabolizing phenoxybenzoates

• Published in: Applied and Environmental Microbiology Vol. 57; no. 5; pp. 1294 - 1300
• Main Authors: Topp, E. (Agriculture Canada, Ottawa, Ontario, Canada), Akhtar, M.H
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01.05.1991
• Subjects: ACIDE BENZOIQUE; ACIDO BENZOICO; benzoates; INSECTICIDAS; INSECTICIDE; metabolism; METABOLISME; METABOLISMO; METABOLITE; metabolites; METABOLITOS; Physiology and Biotechnology; PIRETRINAS SINTETICAS; PSEUDOMONAS; PYRETHRINE DE SYNTHESE; pyrethroid insecticides; strains
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.57.5.1294-1300.1991

3-Phenoxybenzoate is a transient metabolite from the breakdown of a number of pyrethroid insecticides in soil. In this study, we identified and characterized a bacterium which could grow on 3-phenoxybenzoate, converting it to phenol. On the basis of morphological and biochemical features, the 3-phenoxybenzoate-degrading isolate was determined to be a Pseudomonas species, probably a strain of Pseudomonas delafieldii, now designated Pseudomonas strain ET1. Pseudomonas strain ET1 grew on 3-phenoxybenzoate with a generation time of 3 h and a specific rate of metabolism of (2.6 +/- 0.9) X 10-13 g of 3-phenoxybenzoate consumed cell-1 h-1. The Km for 3-phenoxybenzoate metabolism was 1.4 +/- 0.8 micromole. The metabolism of 3-phenoxybenzoate was constitutive and not subject to catabolite repression. The metabolism of a variety of substituted diaryl ether compounds was examined. 3- and 4-Phenoxybenzoates were metabolized, but 2-phenoxybenzoate was not. Phenoxy-substituted benzyl aldehyde was metabolized, but phenoxy-substituted benzyl alcohol, benzene, phenol, and aniline were not. Derivatives of 3-phenoxybenzoate substituted in the 4' position with hydroxyl, methyl, or chlorine were metabolized, yielding the corresponding 4-substituted phenol. 3-(2-Hydroxyphenoxy)benzoate was not metabolized, but 3-phenoxy-4-fluorobenzoate was. These results indicate that the metabolism of the tested diaryl ether compounds was restricted to 4-phenoxybenzoate, 3-phenoxybenzyl aldehyde, and 3-phenoxybenzoate derivatives without a substitution in the 2' position