Cloning and Characterization of Benzoate Catabolic Genes in the Gram-Positive Polychlorinated Biphenyl Degrader Rhodococcus sp. Strain RHA1

• DOI: 10.1128/jb.183.22.6598-6606.2001
• Publication Date: 2002-07-27T09:58:18Z
• Authors: Wataru Kitagawa; Keisuke Miyauchi; Eiji Masai; Masao Fukuda
• Keywords: Catabolism; Gene cluster

ABSTRACT Benzoate catabolism is thought to play a key role in aerobic bacterial degradation of biphenyl and polychlorinated biphenyls (PCBs). catabolic genes were cloned from PCB degrader, Rhodococcus sp. strain RHA1, by using PCR amplification temporal temperature gradient electrophoresis separation. A nucleotide sequence determination revealed that the deduced amino acid sequences encoded RHA1 benzoate genes, benABCDK , exhibit 33 65% identity with those Acinetobacter ADP1. The gene organization differs region was localized on chromosome, contrast which are located linear plasmids. Escherichia coli cells containing benABCD transformed catechol via 2-hydro-1,2-dihydroxybenzoate. They neither 2- nor 4-chlorobenzoates but did transform 3-chlorobenzoate. benA inactivated insertion thiostrepton resistance gene. resultant mutant strain, RBD169, grew benzoate, it not It did, however, diminished growth repression presence high concentration (13 mM). These results indicate could an essential only also RHA1. Six rhodococcal degraders found have homologs benABC . In contrast, two strains cannot homologs, suggesting many contain similar