title: [Detection of biohazardous materials in water upon the characteristics of fluorescent sensor Frex].
abstract: Luminescent bacteria have attracted more and more attention in recent years as an effective mean for biological toxicity of water environment monitoring. First of all, fluorescent protein Frex was correctly expressed in Escherichia coli, and then the effect of toxic substances on microbial metabolism in the water was monitored through the determination of the changes in the fluorescence intensity in bacteria caused by the change of NADH level in the bacteria. Then the effects of culture temperature, inducing time and the final concentration of inductor isopropyl beta-D-thiogalactopyranoside (IPTG) on the expression level and fluorescent activity of the fusion protein Frex were studied. The recombinant fluorescent bacteria was then applied in the initial detection of toxic substances in water environment. Four international standard substances of biological toxicity test including HgCl2, 3,5-dichlorophenol, potassium dichromate, and zinc sulfate heptahydrate were chosen to conduct experimental assay. The results suggested that all of these substances can cause a rapid decrease in the fluorescence of the bacteria. This test method has advantages of rapid reaction and high sensitivity. Meanwhile, the optimization of the conditions for the biological toxicity test lays foundation for subsequent application, and expands the application scope of luminescent bacteria in other aspects.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Zhao
authors.initials: Z
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Cai
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Ou
authors.forename: Fan-Guo
authors.initials: FG
authors.lastname: Meng
mesh_terms: D001681:Biological Assay; D002733:Chlorophenols / Q000032:analysis; D004926:Escherichia coli; D005453:Fluorescence; D007544:Isopropyl Thiogalactoside / Q000737:chemistry; D008164:Luminescent Proteins / Q000737:chemistry*; D008627:Mercuric Chloride / Q000032:analysis; D011192:Potassium Dichromate / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000737:chemistry*; D013696:Temperature; D018675:Toxicity Tests / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D019287:Zinc Sulfate / Q000032:analysis
chemical_list: D002733:Chlorophenols; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D014874:Water Pollutants, Chemical; D007544:Isopropyl Thiogalactoside; D008627:Mercuric Chloride; D019287:Zinc Sulfate; C116190:3,5-dichlorophenol; D011192:Potassium Dichromate