• Korean Journal of Microbiology
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• v.41 no.3
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• pp.195-200
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• 2005

Comamonas sp. strain DJ-12 is a bacterial isolate capable of degrading of 4-chlorobiphenyl (4CB) as a carbon and energy source. The degradation pathway was characterized as being conducted by consecutive reactions of the meta-degradation of 4CB, hydrolytic dechlorination of 4-chlorobenzoate (4CBA), hydroxylation of 4-hydroxybenzoate, and meta-degradation of protocatechuate to product TCA metabolites. The 6.8 kb fragment from the chromosomal DNA of Comamonas sp. strain DJ-12 included the genes encoding for the meta-degradation of PCA; the genes of protocatechuate 4,5-dioxygenase alpha and beta subunits (pmcA and pmcB), 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase (pmcC), 2-pyrone-4,6-dicarboxylate hydrolase (pmcD), 4-oxalomesaconate (OMA) hydratase(pmcE), 4-oxalocitramalate (OCM) aldolase (pmcF), and transporter gene (pmcT). They were organized in the order of pmcT-pmcE-pmcF-pmcD-pmcA-pmcB-pmcC. The amino acid sequences deduced from the nucleotide sequences of pmcABCDEFT genes from Comamonas sp. strain DJ-12 exhibited 94 to $98\%$ homologies with those of Comamonas testosteroni BR6020 and Pseudomonas ochraceae NGJ1, but only 52 to $74\%$ with homologies Sphingomonas paucimobilis SYK-6, Sphingomonas sp. LB126, and Arthrobacter keyseri 12B.