Degradation of phenol and m-toluate in Pseudomonas sp. strain EST1001 and its Pseudomonas putida transconjugants is determined by a multiplasmid system.
The utilization of phenol, m-toluate, and salicylate (Phe+, mTol+, and Sal+ characters, respectively) in Pseudomonas sp. strain EST1001 is determined by the coordinated expression of genes placed in different plasmids, i.e., by a multiplasmid system. The natural multiplasmid strain EST1001 is phenotypically unstable. In its Phe-, mTol-, and Sal- segregants, the plasmid DNA underwent structural rearrangements without a marked loss of plasmid DNA, and the majority of segregants gave revertants. The genes specifying the degradation of phenol and m-toluate were transferable to P. putida PaW340, and in this strain a new multiplasmid system with definite structural changes was formed. The 17-kilobase transposable element, a part of the TOL plasmid pWWO present in the chromosome of PaW340, was inserted into the plasmid DNA in transconjugants. In addition, transconjugant EST1020 shared pWWO-like structures. Enzyme assays demonstrated that ortho-fission reactions were used by bacteria that grew on phenol, whereas m-toluate was catabolized by a meta-fission reaction. Salicylate was a functional inducer of the enzymes of both pathways. The expression of silent metabolic pathways of phenol or m-toluate degradation has been observed in EST1001 Phe- mTol+ and Phe+ mTol- transconjugants. The switchover of phenol degradation from the ortho- to the meta-pathway in EST1033 also showed the flexibility of genetic material in EST1001 transconjugants.
Laboratory of Plasmid Biology, Estonian Biocenter, Tartu, USSR.
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MA
Kivisaar
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JK
Habicht
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Heinaru
D001565:Benzoates / Q000378:metabolism*; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005796:Genes; D005798:Genes, Bacterial; D010101:Oxygen Consumption; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism; D019800:Phenol; D010636:Phenols / Q000378:metabolism*; D010641:Phenotype; D010957:Plasmids; D011549:Pseudomonas / Q000235:genetics* / Q000378:metabolism; D015183:Restriction Mapping; D012459:Salicylates / Q000378:metabolism; D020156:Salicylic Acid; D013045:Species Specificity; D013379:Substrate Specificity
D001565:Benzoates; D004269:DNA, Bacterial; D010636:Phenols; D012459:Salicylates; C009503:3-toluic acid; D019800:Phenol; D010105:Oxygenases; D020156:Salicylic Acid