• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.700-705
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• 2003

Pseudomonas sp. S-47 is capable of degrading benzoate and 4-chlorobenzoate as well as catechol and 4-chlorocatechol via the meta-cleavage pathway. The three enzymes of 2-oxopenta-4-enoate hydratase (OEH), acetaldehyde dehydrogenase (acylating) (ADA), and 2-oxo-4-hydroxypentonate aldolase (HOA) encoded by xylJQK genes are responsible for the three steps after the meta-cleavage of catechol. The nucleotide sequence of the xylJQK genes located in the chromosomal DNA was cloned and analyzed. GC content of xylJ, xylQ, and xylK was 65% and consisted of 786, 924, and 1,041 nucleotides, respectively. The deduced amino acid sequences of xylJ, xylQ, and xylK genes from Pseudomonas sp. S-47 showed 93%, 99%, and 99% identity, compared with those of nahT, nahH, and nahI in Pseudomonas stutzeri An10. However, there were only about 53% to 85% identity with xylJQK of Pseudomonas putida mt-2, dmpEFG of P. putida CF600, aphEFG of Comamonas testosteroni TA441, and ipbEGF of P. putida RE204. On the other hand, the xylLTEGF genes located upstream of xylJQK in the strain S-47 showed high homology with those of TOL plasmid from Pseudomonas putida mt-2. These findings suggested that the xylLTEGFIJQK of Pseudomonas sp. S-47 responsible for complete degradation of benzoate and then catechol via the meta-pathway were phylogenetically recombinated from the genes of Pseudomonas putida mt-2 and Pseudomonas stutzeri An10.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.483-489
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• 2004

Pseudomonas sp. S-47 is a bacterium capable of degrading benzoate as well as 4-chlorobenzoate (4CBA). Benzoate and 4CBA are known to be degraded via a meta-cleavage pathway characterized by a series of enzymes encoded by xyl genes. The meta-cleavage pathway operon in Pseudomonas sp. S-47 encodes a set of enzymes which transform benzoate and 4CBA into TCA cycle intermediates via the meta-cleavage of (4-chloro )catechol to produce pyruvate and acetyl-CoA. In the current study, the meta-pathway gene cluster was cloned from the chromosomal DNA of S-47 strain to obtain pCS1, which included the degradation activities for 4CBA and catechol. The genetic organization of the operon was then examined by cloning the meta-pathway genes into a pBluescript SKII(+) vector. As such, the meta-pathway operon from Pseudomonas sp. S-47 was found to contain 13 genes in the order of xylXYZLTEGFlQKIH. The two regulatory genes, xylS and xylR, that control the expression of the meta-pathway operon, were located adjacently downstream of the meta-pathway operon. The xyl genes from strain S-47 exhibited a high nucleoside sequence homology to those from Pseudomonas putida mt-2, except for the xylJQK genes, which were more homologous to the corresponding three genes from P. stutzeri AN10. One open reading frame was found between the xylH and xylS genes, which may playa role of a transposase. Accordingly, the current results suggest that the xyl gene cluster in Pseudomonas sp. S-47 responsible for the complete degradation of benzoate was recombined with the corresponding genes from P. putida mt-2 and P. stutzeri AN10.