Conjugative plasmid coding for the metabolism of 2-chlorobenzoic acid byPseudomonas aeruginosa

Singh, H. B.; Kahlon, R. S.

doi:10.1007/bf01741850

Cited by 4 publications

(4 citation statements)

References 13 publications

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“…The possibility was considered that, by using 2-CBa as an enrichment substrate, organisms with unusually versatile degradative capabilities can be selected. This, however, appears not to be the case, as other organisms isolated on 2-CBa (2,8,9,33,35,40) have not been reported to utilize a similar range of mono-, di-, or trihalobenzoates. Degradation of both 2-and 3-CBas is proposed to proceed through 3-chlorocatechol ( Fig.…”

Section: Resultsmentioning

confidence: 89%

“…Although plasmid DNA was not isolated by any of the procedures used, the high frequency of spontaneous mutants might be taken as evidence that the genes were carried on an undetected plasmid. Plasmid-borne 2-CBa degradation genes were also implicated in another strain of P. aeruginosa designated B16 (33). Similar to P. aeruginosa JB2, strain B16 also gave rise to spontaneous 2-CBamutants, albeit at a lower frequency (3% in nutrient broth-grown cells).…”

Section: P2mentioning

confidence: 93%

“…The metabolism of these CBas has been well defined and shown to proceed through 3-chlorocatechol and 4-hydroxybenzoate, respectively. The isolation of 2-CBa-degrading bacteria has also been described by a number of researchers (2,8,9,17,33,35,40). Growth of bacteria on dichlorobenzoates (DCBas) is limited to 2,4-DCBa (17, 37, 41), 2,5-DCBa (2), and 3,5-DCBa (18).…”

mentioning

confidence: 91%

“…The genetic basis of CBa degradation has been investigated in several organisms. Plasmid-borne genes have been identified for 3-CBa and 3,5-DCBa degradation (3-5, 13, 38) and implicated for 2-CBa degradation (33). The degradation of 4-CBa, on the other hand, has been reported to be directed by either chromosomal (31) or plasmid-coded (32) genes.…”

mentioning

confidence: 99%

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Degradation of mono-, di-, and trihalogenated benzoic acids by Pseudomonas aeruginosa JB2

Hickey

Focht

1990

Appl Environ Microbiol

137

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Pseudomonas aeruginosa JB2 was isolated from a polychlorinated biphenyl-contaminated soil by enrichment culture containing 2-chlorobenzoate as the sole carbon source. Strain JB2 was subsequently found also to grow on 3-chlorobenzoate, 2,3and 2,5-dichlorobenzoates, 2,3,5-trichlorobenzoate, and a wide range of other monoand dihalogenated benzoic acids. Cometabolism of 2,4-dichlorobenzoate was also observed. Chlorocatechols were the central intermediates of all chlorobenzoate catabolic pathways. Degradation of 2-chlorobenzoate was routed through 3-chlorocatechol, whereas 4-chlorocatechol was identified from the metabolism of both 2,3-and 2,5-dichlorobenzoate. The initial attack on chlorobenzoates was oxygen dependent and most likely mediated by dioxygenases. Although plasmids were not detected in strain JB2, spontaneous mutants were detected in 70% of glycerol-grown colonies. The mutants were all of the following phenotype: benzoate+, 3-chlorobenzoate+, 2-chlorobenzoate-, 2,3-dichlorobenzoate-, 2,5-dichlorobenzoate-. While chlorocatechols were oxidized by the mutants at wild-type levels, oxidation of 2-chloro-and 2,3and 2,5-dichlorobenzoates was substantially diminished. These findings suggested that strain JB2 possessed, in addition to the benzoate dioxygenase, a halobenzoate dioxygenase that was necessary for the degradation of chlorobenzoates substituted in the ortho position. Chlorinated benzoic acids are introduced into the environment chiefly through two sources, namely, herbicides and

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Section: Resultsmentioning

confidence: 89%

Section: P2mentioning

confidence: 93%