algal toxins of salt river reservoirs
play

Algal Toxins of Salt River Reservoirs by Dr. Fiona Jordan Dr. - PowerPoint PPT Presentation

Algal Toxins of Salt River Reservoirs by Dr. Fiona Jordan Dr. David Walker Background Fish kills Fish kills Algal toxins in fish guts Algal toxins in fish guts Neurotoxins Neurotoxins Hepatotoxins Hepatotoxins


  1. Algal Toxins of Salt River Reservoirs by Dr. Fiona Jordan Dr. David Walker

  2. Background � Fish kills Fish kills � � Algal toxins in fish guts Algal toxins in fish guts � � Neurotoxins Neurotoxins � � Hepatotoxins Hepatotoxins � � Misleading aqueous samples Misleading aqueous samples � � Low Low- -level toxins level toxins � � Short half Short half- -life life � � Low Low- -level algal toxin level algal toxin- -producers producers � � Anabaena & Cylindrospermopsis Anabaena & Cylindrospermopsis � Photo courtesy of Dave Rigo, AzG&F Dept.

  3. Project Goals � Improve toxin detection � Protect public health � Predict & possibly prevent future fish kills.

  4. Aqueous Samples

  5. Known Toxin-Producers Cylindrospermopsis Microcystis Anabaena Anatoxin-a Microcystin-LR Cylindrospermopsin

  6. Genetic Characterization Dendrogram of cyanobacterial 16 S genes (generated by RFLP). Scale bar = similarity coefficients. Numbers 1–4 = clades . Symbols : � neurotoxic ; � non-toxic ; � hepatotoxic ; � toxicity not determined ; � type of toxicity unknown. Lyra et al. (2001)

  7. Lyra et al. (2001) Dendrogram of cyanobacterial genomic fingerprints (generated by REP- and ERIC-PCR). Scale = similarity coefficients. Numbers 1–4 = groups . Symbols : � neurotoxic ; � non-toxic ; � hepatotoxic ; � toxicity not determined ; � type of toxicity unknown.

  8. Toxin Production Environmental triggers ?? Salinity, pH, light, temperature, DOC Single isolate vs mixed culture Characterize toxins HPLC & LCMS –structure and quantity LD 50 ??? • Characterize toxin producers Genes ???

  9. Objectives I. Isolate suspect algal species I. Obtain axenic cultures II. Factors influencing toxin production I. Biotic and abiotic II. Biological assays III. Characterize toxins & isolates

  10. Axenic Cultures • Isolate individual species • Axenic • bacterial-free • uni-algal • Pure cultures • solid or liquid media • Genetic characterization http://honeybee.helsinki.fi/mmkem/MIKRO/PROJEKTI/syano/pullot.jpg

  11. Fish Bioassays � Expose fish to � Individual algae � Environmental conditions = algae � Algal supernatant � Mixed population � Determine lethality/toxicity � Identify toxins � Liquid and tissue � Type and quantity

Recommend


More recommend