Structural analysis of the fcbABC gene cluster responsible for hydrolytic dechlorination of 4-chlorobenzoate from pJS1 plasmid of Comamonas sp. P08

Bacterial strain No. P08 isolated from wastewater at the Cheongju industrial complex was found to be capable of degrading 4-chlorobenzoate under aerobic condition. P08 was identified as Comamonas sp. from its cellular fatty acid composition and 16S rDNA sequence. The fcb genes, responsible for the hydrolytic dechlorination of 4-chlorobenzoate, were cloned from the plasmid pJS1 of Comamonas sp. P08. The fcb gene cluster of comamonas sp. P08 was organized in the order fcbB-fcbA-fcbT1-fcbT2-fcbT3-fcbC. This organization of the fcb genes was very similar to that of the fcb genes carried on the chromosomal DNA of Pseudomonas sp. DJ-12. However, it differed from the fcbA-fcbB-fcbC ordering of Arthrobacter sp. SU. The nucleotide sequences of the fcbABC genes of strain P08 showed 98% and 53% identities to those of Pseudomonas sp. DJ-12 and Arthrobacter sp. SU, respectively. This suggests that the fcb genes might have been derived from Pseudomonas sp. DJ-12 to form plasmid pJS1 in Comamonas sp. P08, or that the fcb genes in strain DJ-12 were transposed from Comamonas sp. P08 plasmid.