Specificity re-evaluation of oligonucleotidic probes for the detection of marine picoplankton by Tyramide Signal Amplification-Fluorescent in situ Hybridization

Supplementary material to Riou et al. 2017 Frontier in MicrobiologySupplementary material to Riou et al. 2017 Specificity of re-evaluation of oligonucleotides probes for the detection of marine picoplankton by Tyramide Signal Amplification-Fluorescent in situ Hybridizatio

Specificity re-evaluation of oligonucleotidic probes for the detection of marine picoplankton by Tyramide Signal Amplification-Fluorescent in situ Hybridization

Supplementary material to Riou et al. 2017 Frontier in MicrobiologySupplementary material to Riou et al. 2017 Specificity of re-evaluation of oligonucleotides probes for the detection of marine picoplankton by Tyramide Signal Amplification-Fluorescent in situ Hybridizatio

Specificity Re-evaluation of Oligonucleotide Probes for the Detection of Marine Picoplankton by Tyramide Signal Amplification-Fluorescent In Situ Hybridization

Oligonucleotide probes are increasingly being used to characterize natural microbial assemblages by Tyramide Signal Amplification-Fluorescent in situ Hybridization (TSA-FISH, or CAtalysed Reporter Deposition CARD-FISH). In view of the fast-growing rRNA databases, we re-evaluated the in silico specificity of eleven bacterial and eukaryotic probes and competitor frequently used for the quantification of marine picoplankton. We performed tests on cell cultures to decrease the risk for non-specific hybridization, before they are used on environmental samples. The probes were confronted to recent databases and hybridization conditions were tested against target strains matching perfectly with the probes, and against the closest non-target strains presenting one to four mismatches. We increased the hybridization stringency from 55 to 65% formamide for the Eub338+EubII+EubIII probe mix to be specific to the Eubacteria domain. In addition, we found that recent changes in the Gammaproteobacteria classification decreased the specificity of Gam42a probe, and that the Roseo536R and Ros537 probes were not specific to, and missed part of the Roseobacter clade. Changes in stringency conditions were important for bacterial probes; these induced, respectively, a significant increase, in Eubacteria and Roseobacter and no significant changes in Gammaproteobacteria concentrations from the investigated natural environment. We confirmed the eukaryotic probes original conditions, and propose the Euk1209+NChlo01+Chlo02 probe mix to target the largest picoeukaryotic diversity. Experiences acquired through these investigations leads us to propose the use of seven steps protocol for complete FISH probe specificity check-up to improve data quality in environmental studies

Specificity re-evaluation of oligonucleotidic probes for the detection of marine picoplankton by Tyramide Signal Amplification-Fluorescent in situ Hybridization

Supplementary material to Riou et al. 2017 Frontier in MicrobiologySupplementary material to Riou et al. 2017 Specificity of re-evaluation of oligonucleotides probes for the detection of marine picoplankton by Tyramide Signal Amplification-Fluorescent in situ Hybridizatio

NUTRIENTS AND SAHARAN DUST EVENTS CONTROL UNICELLULAR DIAZOTROPHIC CYANOBACTERIA DEVLOPMENT IN OLIGOTROPHIC MEDITERRANEAN SEA

International audienc

NUTRIENTS AND SAHARAN DUST EVENTS CONTROL UNICELLULAR DIAZOTROPHIC CYANOBACTERIA DEVLOPMENT IN OLIGOTROPHIC MEDITERRANEAN SEA

International audienc

NUTRIENTS AND SAHARAN DUST EVENTS CONTROL UNICELLULAR DIAZOTROPHIC CYANOBACTERIA DEVLOPMENT IN OLIGOTROPHIC MEDITERRANEAN SEA

International audienc

NUTRIENTS AND SAHARAN DUST EVENTS CONTROL UNICELLULAR DIAZOTROPHIC CYANOBACTERIA DEVLOPMENT IN OLIGOTROPHIC MEDITERRANEAN SEA

International audienc

NUTRIENTS AND SAHARAN DUST EVENTS CONTROL UNICELLULAR DIAZOTROPHIC CYANOBACTERIA DEVLOPMENT IN OLIGOTROPHIC MEDITERRANEAN SEA

International audienc

Evaluation de la contamination en 2,4,6-tribromophenol d'eau et d'organismes marins exposés à des rejets de chloration

International audience2,4,6-tribromophenol (TBP) is implied in the production of brominated flame retardants but is also a major chlorination by-product in seawater. A growing number of studies indicate that TBP is highly toxic to the marine biota, but the contribution of anthropogenic sources among natural production is still under question concerning its bioaccumulation in marine organisms. Here, several water sampling campaigns were carried out in the industrialized Gulf of Fos and clearly showed the predominant incidence of industrial chlorination discharges on the TBP levels in water, at the 1-10 ng L-1 level in average and reaching up to 580 ng L-1 near the outlets. The bioaccumulation of TBP was measured in 90 biota samples of the Gulf of Fos. The concentrations found in European conger muscle tissues (140 to 1000 ng g-1 lipid weight, in average), purple sea urchin gonads (830 to 880 ng g-1 lipid weight, in average), and Mediterranean mussel body (1500 to 2000 ng g-1 lipid weight, in average) were above all published references. Significant correlations with fish length (European conger) and gonad somatic index (purple sea urchin) were also identified. Comparatively, fish, urchins and mussels from other Mediterranean sites analyzed within this study showed a lower bioaccumulation level of TBP, consistently with what found elsewhere. Industrial outflows were thus identified as hotspots for TBP in seawater and marine organisms. The environmental risk assessment indicated a high potential toxicity in the industrial Gulf of Fos, in particular near the outlets, and a limited threat to human but toxicological references are lacking