title: Utilization of interferometric light microscopy for the rapid analysis of virus abundance in a river.
abstract: There is a constant need for direct counting of biotic nanoparticles such as viruses to unravel river functioning. We used, for the first time in freshwater, a new method based on interferometry differentiating viruses from other particles such as membrane vesicles. In the French Marne River, viruses represented between 42 and 72% of the particles. A spring monitoring in 2014 revealed their increase (2.1 × 107to 2.1 × 108mL-1) linked to an increase in algal biomass and diversity of bacterial plankton. Predicted virus size distributions were in agreement with transmission electron microscopy analysis suggesting a dominance of large viruses (≥60 nm).
authors.affiliation: UMR 7619 METIS, Sorbonne Universités, CNRS, Univ Paris 06, EPHE, 4 place Jussieu, 75005 Paris, France. Electronic address: celine.amsaleg@upmc.fr.
authors.forename: Céline
authors.initials: C
authors.lastname: Roose-Amsaleg
authors.affiliation: Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, PSL Research University, CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France; Institut Langevin, ESPCI ParisTech, PSL Research University, CNRS UMR 7587, 1 rue Jussieu, 75005 Paris, France. Electronic address: yasmina.fedala@gmail.com.
authors.forename: Yasmina
authors.initials: Y
authors.lastname: Fedala
authors.affiliation: Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie UMR 7590, Sorbonne Universités, Univ Paris 06, CNRS, MNHN, IRD, 4 place Jussieu, 75005 Paris, France. Electronic address: Catherine.Venien@impmc.upmc.fr.
authors.forename: Catherine
authors.initials: C
authors.lastname: Vénien-Bryan
authors.affiliation: UMR 7619 METIS, Sorbonne Universités, CNRS, Univ Paris 06, EPHE, 4 place Jussieu, 75005 Paris, France. Electronic address: josette.garnier@upmc.fr.
authors.forename: Josette
authors.initials: J
authors.lastname: Garnier
authors.affiliation: Institut Langevin, ESPCI ParisTech, PSL Research University, CNRS UMR 7587, 1 rue Jussieu, 75005 Paris, France. Electronic address: claude.boccara@espci.fr.
authors.forename: Albert-Claude
authors.initials: AC
authors.lastname: Boccara
authors.affiliation: Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, PSL Research University, CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France; Atelier de Bioinformatique, UMR 7205 ISYEB Sorbonne Universités, Univ Paris 06, CNRS, MNHN, EPHE, 45 rue Buffon, 75005 Paris, France. Electronic address: boccara.martine@gmail.com.
authors.forename: Martine
authors.initials: M
authors.lastname: Boccara
mesh_terms: D018533:Biomass; D000458:Cyanobacteria / Q000821:virology; D005618:Fresh Water / Q000821:virology; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D008857:Microscopy, Interference; D010933:Plankton / Q000821:virology; D045483:Rivers / Q000821:virology*; D012621:Seasons; D014780:Viruses / Q000302:isolation & purification* / Q000648:ultrastructure*
keywords: Interferometric light microscopy; Membrane vesicle; River; Virus