BIOSENSING OF BENZENE-DERIVATIVES IN THE ENVIRONMENT BY LUMINESCENT ESCHERICHIA-COLI

Sensitive and convenient biosensing of environmental pollutants has be en developed by fusing a gene of firefly luciferase to the TOL plasmid . TOL plasmid of Pseudomonas putida encodes a series of enzymes for de gradation of benzene and its derivatives. The expression of these enzy mes is controlled with the regulating proteins xylR and xylS, whose pr omoters are activated in the presence of aromatic compounds. The struc tural gene of firefly luciferase, as a reporter enzyme, was inserted u nder the control of the promoter of xylS protein, and gene fusion plas mid pTSN316 was constructed. The recombinant Escherichia coli transfor med with this plasmid was applied to the environmental biosensing of b enzene derivatives. The expression of luciferase was induced in the pr esence of aromatic compounds and the lower detection limit for m-xylen e was 5 mu M.