Detection of Aromatic Pollutants by Bacterial Biosensors Bearing Gene Fusions Constructed with the dnaK Promoter of Pseudomonas sp. DJ-12

摘要

Gene fusions were constructed by the transcriptional fusion of the dnaK promoter of Pseudomonas-sp. DJ-12 or E. coli to the lux or luc marker gene. The dnaKp- Jy.hixCDABE bioluminescent fusion in the biosensor using the Pseudomonassp. DJ-12 dnaK promoter exhibited about 5-fold more extensiveresponse to ethanol than that of dna.Kp-EC:: IuxCDABE. The bioluminescent response of the dnaK-DJ::luc fusion toethanol was much weaker than those of the other fusions. Thebiosensor harboring the dnaKp-DJ:diaCDABE fusion was examined for its bioluminescence production based on exposure to aromatic compounds, such as biphenyl, 4-chlorobiphenyl (4CB), 4-hydroxybenzoate (4HBA), and catechol. In particular, the bioluminescence produced by the dhaKp-DJ:duxCDABE fusion was most sensitive to 1 mM biphenyl and 4CB when exposed for 80 min, and the responses were also veiy strong to other aromatics. Therefore, the biosensor bearing the dnaKp-DJr.luxCDABE fusion would appear to be the most useful for the detection of aromatics and other pollutants.