Identification of a meta-cleavage pathway for metabolism of phenoxyacetic acid and phenol in Pseudomonas cepacia AC1100.
Pseudomonas cepacia strain AC1100 grows luxuriantly on 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) but does not utilize phenoxyacetic acid. After long-term selective pressure on phenoxyacetic acid, mutants designated as strain PAA, capable of utilizing phenoxyacetic acid as well as phenol, emerged spontaneously at a frequency of 1 x 10(-8). A deletion mutant strain PT88, which is devoid of a part of 2,4,5-T metabolic pathway, generated neither phenoxyacetic acid utilizing nor phenol-utilizing mutants. The wild type (Wt) strain AC1100 and all its mutants utilized benzoate via ortho-cleavage pathway. However, only mutant strain PAA harbored the whole set of enzymes required for utilization of phenol via meta-cleavage pathway. The results suggest that Wt strain AC1100 carries silent genes for meta-cleavage pathway which are expressed in strain PAA enabling it to utilize phenoxyacetic acid and phenol. Gene activation is presumed to be due to the translocation of insertion elements.
Ghadi
S C
SC
Department of Marine Sciences and Marine Biotechnology, Goa University, India.
Sangodkar
U M
UM
D001673:Biodegradation, Environmental; D016956:Burkholderia cepacia / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D050557:Catechol 2,3-Dioxygenase; D049308:Dioxygenases; D006868:Hydrolysis; D006899:Mixed Function Oxygenases / Q000378:metabolism; D009154:Mutation; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000378:metabolism; D019800:Phenol; D010636:Phenols / Q000378:metabolism*; D010642:Phenoxyacetates / Q000378:metabolism*
D010636:Phenols; D010642:Phenoxyacetates; D019800:Phenol; D006899:Mixed Function Oxygenases; D010105:Oxygenases; D049308:Dioxygenases; D050557:Catechol 2,3-Dioxygenase; C022336:phenol 2-monooxygenase