title: Performance evaluation of phycocyanin probes for the monitoring of cyanobacteria.
abstract: The performance of two field probes (YSI 6600 and TriOS), used for the measurement of in vivo phycocyanin fluorescence, was compared and validated in the laboratory in 2008 and 2009 with cultures of Microcystis aeruginosa and field samples. The background noise of the two probes was low and the detection limits were estimated at 1500 cells mL(-1) for the YSI and 0.69 µg PC L(-1) for the TriOS. The linearity and repeatability of both probes have been excellent. Strong relationships were observed between the in vivo fluorescence and the total cyanobacterial biovolume (R(2) = 0.82 YSI; 0.83 TriOS) or the abundance (R(2) = 0.71 YSI; 0.75 TriOS) of cyanobacteria. However, the difference between cell densities determined by microscopy and measured by the YSI can be very large and has been associated to the variability of cell volume among cyanobacteria. This last observation makes the YSI a qualitative tool if a post-calibration is not done. The analysis of filtrated samples showed that dissolved phycocyanin (extracellular) may represent a significant fluorescence signal. No relationship could be established between the abundance, the total cyanobacterial biovolume or the in vivo fluorescence of phycocyanin and the concentrations of cyanotoxins (R(2) ≤ 0.22).
authors.affiliation: Centre d'expertise en analyse environnementale, MDDEP, 2700 rue Einstein, Québec (Qc), G1P 3W8, Canada. christian.bastien@mddep.gouv.qc.ca
authors.forename: Christian
authors.initials: C
authors.lastname: Bastien
authors.forename: Richard
authors.initials: R
authors.lastname: Cardin
authors.forename: Eloïse
authors.initials: E
authors.lastname: Veilleux
authors.forename: Christian
authors.initials: C
authors.lastname: Deblois
authors.forename: Annabelle
authors.initials: A
authors.lastname: Warren
authors.forename: Isabelle
authors.initials: I
authors.lastname: Laurion
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D046931:Microcystis / Q000737:chemistry / Q000254:growth & development*; D008856:Microscopy, Fluorescence; D010798:Phycocyanin / Q000032:analysis*; D012015:Reference Standards; D014876:Water Pollution / Q000032:analysis*
chemical_list: D005456:Fluorescent Dyes; D010798:Phycocyanin