title: Recombinant microorganisms as environmental biosensors: pollutants detection by Escherichia coli bearing fabA'::lux fusions.
abstract: A set of genetically engineered Escherichia coli strains was constructed, in which the promoter of the fabA gene is fused to Vibrio fischeri luxCDABE either in a multi-copy plasmid or as a single copy chromosomal integration. The fabA gene codes for beta-hydroxydecanoyl-ACP dehydrase, a key enzyme in the synthesis of unsaturated fatty acids, and is induced when fatty acid biosynthesis pathways are interrupted. A dose-dependent and highly sensitive bioluminescent response to a variety of chemicals was controlled by the fadR gene. A tolC mutant E. coli host displayed generally lower detection threshold for toxicants. A chromosomal integration of a single copy of the fabA'::lux fusion led to a markedly lower background luminescence, but did not yield an improvement in overall performance. It is proposed that these or similarly constructed reporters of fatty acid biosynthesis inhibition may serve as novel microbial toxicity biosensors.
authors.affiliation: Division of Environmental Sciences, The Fredy and Nadine Herrmann Graduate School of Applied Science, The Hebrew University, Jerusalem 91904, Israel.
authors.forename: Ofra
authors.initials: O
authors.lastname: Bechor
authors.forename: Dana R
authors.initials: DR
authors.lastname: Smulski
authors.forename: Tina K
authors.initials: TK
authors.lastname: Van Dyk
authors.forename: Robert A
authors.initials: RA
authors.lastname: LaRossa
authors.forename: Shimshon
authors.initials: S
authors.lastname: Belkin
mesh_terms: D019677:Artificial Gene Fusion; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001483:Base Sequence; D015374:Biosensing Techniques; D001709:Biotechnology; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D054889:Fatty Acid Synthase, Type II; D005798:Genes, Bacterial; D006836:Hydro-Lyases / Q000235:genetics; D008163:Luminescent Measurements; D026901:Membrane Transport Proteins; D009154:Mutation; D010957:Plasmids / Q000235:genetics
chemical_list: D001425:Bacterial Outer Membrane Proteins; D004785:Environmental Pollutants; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; C073126:tolC protein, E coli; D006836:Hydro-Lyases; C047118:3-hydroxyacyl-(acyl-carrier-protein) dehydratase; D054889:Fatty Acid Synthase, Type II