Publications

• Genetic organization and regulation of a meta cleavage pathway for catechols produced from catabolism of toluene, benzene, phenol, and cresols by Pseudomonas pickettii PKO1.

  Kukor J.J., Olsen R.H.

  Plasmid pRO1957 contains a 26.5-kb BamHI restriction endonuclease-cleaved DNA fragment cloned from the chromosome of Pseudomonas pickettii PKO1 that allows P. aeruginosa PAO1c to grow on toluene, benzene, phenol, or m-cresol as the sole carbon source. The genes encoding enzymes for meta cleavage o ... >> More

  Plasmid pRO1957 contains a 26.5-kb BamHI restriction endonuclease-cleaved DNA fragment cloned from the chromosome of Pseudomonas pickettii PKO1 that allows P. aeruginosa PAO1c to grow on toluene, benzene, phenol, or m-cresol as the sole carbon source. The genes encoding enzymes for meta cleavage of catechol or 3-methylcatechol, derived from catabolism of these substrates, were subcloned from pRO1957 and were shown to be organized into a single operon with the promoter proximal to tbuE. Deletion and analysis of subclones demonstrated that the order of genes in the meta cleavage operon was tbuEFGKIHJ, which encoded catechol 2,3-dioxygenase, 2-hydroxymuconate semialdehyde hydrolase, 2-hydroxymuconate semialdehyde dehydrogenase, 4-hydroxy-2-oxovalerate aldolase, 4-oxalocrotonate decarboxylase, 4-oxalocrotonate isomerase, and 2-hydroxypent-2,4-dienoate hydratase, respectively. The regulatory gene for the tbuEFGKIHJ operon, designated tbuS, was subcloned into vector plasmid pRO2317 from pRO1957 as a 1.3-kb PstI fragment, designated pRO2345. When tbuS was not present, meta pathway enzyme expression was partially derepressed, but these activity levels could not be fully induced. However, when tbuS was present in trans with tbuEFGKIHJ, meta pathway enzymes were repressed in the absence of an effector and were fully induced when an effector was present. This behavior suggests that the gene product of tbuS acts as both a repressor and an activator. Phenol and m-cresol were inducers of meta pathway enzymatic activity. Catechol, 3-methylcatechol, 4-methylcatechol, o-cresol, and p-cresol were not inducers but could be metabolized by cells previously induced by phenol or m-cresol. << Less

  J Bacteriol 173:4587-4594(1991) [PubMed] [EuropePMC]

• Biodegradation of 2-nitrotoluene by Pseudomonas sp. strain JS42.

  Haigler B.E., Wallace W.H., Spain J.C.

  A strain of Pseudomonas sp. was isolated from nitrobenzene-contaminated soil and groundwater on 2-nitrotoluene as the sole source of carbon, energy, and nitrogen. Bacterial cells growing on 2-nitrotoluene released nitrite into the growth medium. The isolate also grew on 3-methylcatechol, 4-methylc ... >> More

  A strain of Pseudomonas sp. was isolated from nitrobenzene-contaminated soil and groundwater on 2-nitrotoluene as the sole source of carbon, energy, and nitrogen. Bacterial cells growing on 2-nitrotoluene released nitrite into the growth medium. The isolate also grew on 3-methylcatechol, 4-methylcatechol, and catechol. 2-Nitrotoluene, 3-methylcatechol, and catechol stimulated oxygen consumption by intact cells regardless of the growth substrate. Crude extracts from the isolate contained catechol 2,3-dioxygenase and 2-hydroxy-6-oxohepta-2,4-dienoate hydrolase activity. The results suggest that 2-nitrotoluene is subject to initial attack by a dioxygenase enzyme that forms 3-methylcatechol with concomitant release of nitrite. The 3-methylcatechol is subsequently degraded via the meta ring fission pathway. << Less

  Appl. Environ. Microbiol. 60:3466-3469(1994) [PubMed] [EuropePMC]

• Metabolism of phenol and cresols by mutants of Pseudomonas putida.

  Bayly R.C., Wigmore G.J.

  Mutant strains of Pseudomonas putida strain U have been obtained which are deficient in enzymes of the degradative pathways of phenol and cresols. Mutant strains deficient in catechol 2, 3-oxygenase accumulated the appropriate catechol derivative from cresols. A mutant strain which would not grow ... >> More

  Mutant strains of Pseudomonas putida strain U have been obtained which are deficient in enzymes of the degradative pathways of phenol and cresols. Mutant strains deficient in catechol 2, 3-oxygenase accumulated the appropriate catechol derivative from cresols. A mutant strain which would not grow on either phenol or a cresol was shown to be deficient in both 2-hydroxymuconic semialdehyde hydrolase and a nicotinamide adenine dinucleotide, oxidized form, (NAD(+))-dependent aldehyde dehydrogenase. When this strain was grown in the presence of phenol or a cresol, the appropriate product of meta fission of these compounds accumulated in the growth medium. A partial revertant of this mutant strain, which was able to grow on ortho- and meta-cresol but not para-cresol, was shown to have regained only the hydrolase activity. This strain was used to show that the products of meta ring fission of the cresols and phenol are metabolized as follows: (i) ortho- and meta-cresol exclusively by a hydrolase; (ii) para-cresol exclusively by a NAD(+)-dependent aldehyde dehydrogenase; (iii) phenol by both a NAD(+)-dependent dehydrogenase and a hydrolase in the approximate ratio of 5 to 1. This conclusion is supported by the substrate specificity and enzymatic activity of the hydrolase and NAD(+)-dependent aldehyde dehydrogenase enzymes of the wild-type strain. The results are discussed in terms of the physiological significance of the pathway. Properties of some of the mutant strains isolated are discussed. << Less

  J Bacteriol 113:1112-1120(1973) [PubMed] [EuropePMC]

• Location and sequence of the todF gene encoding 2-hydroxy-6-oxohepta-2,4-dienoate hydrolase in Pseudomonas putida F1.

  Menn F.M., Zylstra G.J., Gibson D.T.

  The gene (todF) encoding 2-hydroxy-6-oxohepta-2,4-dienoate hydrolase in Pseudomonas putida F1 was shown to be located upstream of the todC1C2BADE genes. The latter form part of the tod operon and encode the enzymes responsible for the initial reactions in toluene degradation. The nucleotide (nt) s ... >> More

  The gene (todF) encoding 2-hydroxy-6-oxohepta-2,4-dienoate hydrolase in Pseudomonas putida F1 was shown to be located upstream of the todC1C2BADE genes. The latter form part of the tod operon and encode the enzymes responsible for the initial reactions in toluene degradation. The nucleotide (nt) sequence of todF was determined and the deduced amino acid (aa) sequence revealed that the hydrolase contains 276 aa with a Mr of 30,753. The deduced aa sequence was 63.5% homologous to that reported for 2-hydroxymuconic semialdehyde hydrolase which is involved in phenol degradation by Pseudomonas CF600. << Less

  Gene 104:91-94(1991) [PubMed] [EuropePMC]