Construction of transformant reporters carrying fused genes using pcbC promoter of Pseudomonas sp DJ-12 for detection of aromatic pollutants.

Three reporter gene fusions were constructed by a transcriptional fusion method using the pcbC promoter of Pseudomonas sp. DJ-12, which can extensively degrade biphenyl and 4-chlorobiphenyl by meta-cleavage dioxygenase. The reporter genes used for the construction of the fusions were luc, luxCDABE and gfpuv. The reporter fusion plasmids were introduced into E. coli XL1-Blue, and the transformant reporters examined for the production of fluorescent light by exposure to aromatic compounds, such as biphenyl, 4-chlorobiphenyl, 4-hydroxybiphenyl, 2,3-dihydroxybiphenyl, catechol and 4-chlorocatechol. The reporter cells, carrying the respective gene fusions, responded well to the aromatics when exposed to a concentration of 0.1 mM for 10 min. In particular, the reporter cells carrying the pcbCp::luxCDABE gene fusion produced bioluminescence most extensively to the above mentioned aromatics. This means that the pcbCp::luxCDABE reporter gene fusion may be useful in bacterial biosensors for the detection of aromatic pollutants in the environment, and may also be valuable for examining the bioavailability of the inducing pollutants.