title: Bacterial host and reporter gene optimization for genetically encoded whole cell biosensors.
abstract: Whole-cell biosensors based on reporter genes allow detection of toxic metals in water with high selectivity and sensitivity under laboratory conditions; nevertheless, their transfer to a commercial inline water analyzer requires specific adaptation and optimization to field conditions as well as economical considerations. We focused here on both the influence of the bacterial host and the choice of the reporter gene by following the responses of global toxicity biosensors based on constitutive bacterial promoters as well as arsenite biosensors based on the arsenite-inducible Parspromoter. We observed important variations of the bioluminescence emission levels in five different Escherichia coli strains harboring two different lux-based biosensors, suggesting that the best host strain has to be empirically selected for each new biosensor under construction. We also investigated the bioluminescence reporter gene system transferred into Deinococcus deserti, an environmental, desiccation- and radiation-tolerant bacterium that would reduce the manufacturing costs of bacterial biosensors for commercial water analyzers and open the field of biodetection in radioactive environments. We thus successfully obtained a cell survival biosensor and a metal biosensor able to detect a concentration as low as 100 nM of arsenite in D. deserti. We demonstrated that the arsenite biosensor resisted desiccation and remained functional after 7 days stored in air-dried D. deserti cells. We also report here the use of a new near-infrared (NIR) fluorescent reporter candidate, a bacteriophytochrome from the magnetotactic bacterium Magnetospirillum magneticum AMB-1, which showed a NIR fluorescent signal that remained optimal despite increasing sample turbidity, while in similar conditions, a drastic loss of the lux-based biosensors signal was observed.
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Brutesco
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Prévéral
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Escoffier
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France.
authors.forename: Elodie C T
authors.initials: ECT
authors.lastname: Descamps
authors.affiliation: Université de Lyon, Lyon, 69003, France.|INSA de Lyon, Villeurbanne, 69621, France.|CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, Université Lyon 1, Villeurbanne, 69622, France.
authors.forename: Elsa
authors.initials: E
authors.lastname: Prudent
authors.affiliation: Université de Lyon, Lyon, 69003, France.|INSA de Lyon, Villeurbanne, 69621, France.|CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, Université Lyon 1, Villeurbanne, 69622, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Cayron
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France.
authors.forename: Louis
authors.initials: L
authors.lastname: Dumas
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France.
authors.forename: Manon
authors.initials: M
authors.lastname: Ricquebourg
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France.
authors.forename: Géraldine
authors.initials: G
authors.lastname: Adryanczyk-Perrier
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France.
authors.forename: Arjan
authors.initials: A
authors.lastname: de Groot
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Garcia
authors.affiliation: Université de Lyon, Lyon, 69003, France.|INSA de Lyon, Villeurbanne, 69621, France.|CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, Université Lyon 1, Villeurbanne, 69622, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Rodrigue
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France.
authors.forename: David
authors.initials: D
authors.lastname: Pignol
authors.affiliation: CEA, DRF, BIAM, Lab Bioenerget Cellulaire, Saint-Paul-lez-Durance, 13108, France. nicolas.ginet@cea.fr.|CNRS, UMR Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, 13108, France. nicolas.ginet@cea.fr.|Aix-Marseille Université, Saint-Paul-lez-Durance, 13108, France. nicolas.ginet@cea.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ginet
mesh_terms: D018053:Arsenites / Q000737:chemistry* / Q000378:metabolism; D015374:Biosensing Techniques; D034301:Deinococcus / Q000235:genetics / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D017930:Genes, Reporter; D049453:Luciferases, Bacterial / Q000235:genetics / Q000378:metabolism*; D019216:Metals, Heavy / Q000633:toxicity; D011401:Promoter Regions, Genetic; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical
chemical_list: D018053:Arsenites; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D014867:Water; D049453:Luciferases, Bacterial; C015001:arsenite
keywords: Arsenite biosensor; Bacteriophytochrome; Bioluminescence; Deinococcus deserti; Desiccation; Near-infrared fluorescent reporter