title: Evaluation of ChemChrome V6 for bacterial viability assessment in waters.
abstract: The efficiency of ChemChrome B (CB) and ChemChrome V6 (CV6) dyes to stain viable bacterial cells in water was compared. Both dyes are fluorogenic esters converted to free fluorescein by esterase activity. The dyes were applied to a wide variety of bacterial species, including those poorly stained by CB, and to natural waters. Some species tested gave unacceptable low fluorescence intensities by being inefficiently or non-labelled with the CB. In contrast, CV6-stained bacteria were easily detected by both flow cytometry and solid-phase cytometry. As a consequence, higher viable cell counts were found with CV6 compared with CB in natural waters. Viable counts determined by CV6 staining were always higher than cfu counts. In contrast, respiring cell counts (CTC) were always lower than CV6 counts and, in the case of tap and mineral waters, they were lower than cfu counts.
authors.affiliation: Observatoire Océanologique, Centre National de la Recherche Scientifique, Institut National des Sciences de l'Univers et Université Pierre et Marie Curie, Banyuls-sur-Mer, France.
authors.forename: N
authors.initials: N
authors.lastname: Parthuisot
authors.forename: P
authors.initials: P
authors.lastname: Catala
authors.forename: K
authors.initials: K
authors.lastname: Lemarchand
authors.forename: J
authors.initials: J
authors.lastname: Baudart
authors.forename: P
authors.initials: P
authors.lastname: Lebaron
mesh_terms: D001419:Bacteria / Q000254:growth & development* / Q000378:metabolism; D015169:Colony Count, Microbial; D003592:Cytophotometry / Q000379:methods; D004950:Esterases / Q000378:metabolism; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000378:metabolism*; D013194:Staining and Labeling; D013777:Tetrazoles / Q000378:metabolism; D013778:Tetrazolium Salts; D014871:Water Microbiology
chemical_list: D005456:Fluorescent Dyes; D013777:Tetrazoles; D013778:Tetrazolium Salts; C075453:5-cyano-2,3-ditolyltetrazolium; D004950:Esterases