Detection and Identification of the Toxins from Pfiesteria and Related Harmful Algal Blooms

EPA Grant Number: R826655
Title: Detection and Identification of the Toxins from Pfiesteria and Related Harmful Algal Blooms
Investigators: Gawley, Robert E. , Baden, Daniel G.
Institution: University of Miami
Current Institution: University of Miami , University of North Carolina at Chapel Hill
EPA Project Officer: Packard, Benjamin H
Project Period: August 1, 1998 through July 31, 2002
Project Amount: $353,975
RFA: Ecology and Oceanography of Harmful Algal Blooms (1998) RFA Text |  Recipients Lists
Research Category: Water Quality , Nanotechnology , Harmful Algal Blooms , Water , Aquatic Ecosystems


The "Cell from Hell," Pfiesteria piscicada, has emerged as a major ecological problem to the economies of several eastern seaboard states, and to the health of fishermen, boaters, and residents of the areas where blooms of this dinoflagellate occur. Pfiesteria is a dinoflagellate that, when it accumulates to toxic concentrations in response to unknown stimuli, it results in huge fish-kills. The stimuli are probably human in origin, with one likely possibility being agricultural runoff. Objectives:
  1. Grow cultures of Pfiesteria and related "Shephard's Crook" dinoflagellates (a not-yet-assigned organism that is present in many Pfiesteria outbreaks), as well as Scripsiellas, Glenodiniums, and Gyrodiniums dinoflagellates. Concentrate the toxins on reversed-phase C-18 HPLC columns by filtration of aquarium water, then elute fractions with organic solvents. Identify toxic fractions by whole-fish bioassay using Tilapia fish fry. Purify the toxins to homogeneity, accumulate enough to allow chemical characterization, and elucidate the toxins' structure using mass spectrometry, nuclear magnetic resonance, infrared spectroscopy, and perhaps X-ray crystallography.
  2. Use the techniques of combinatorial chemistry to design ligand-selective host(s) that bind toxins from Pfiesteria and related dinoflagellates, while simultaneously effecting a visible signal of such binding in the form of enhanced fluorescence, seeking a host with optimum response to toxin and minimum response to other possible guests. Since the structures of the toxins are not known, this will be accomplished by seeking a correlation of toxicity in toxic fractions with fluorescence signaling of library members on polymer beads. The most highly fluorescent beads could then be produced in bulk for use as a toxin sensor.
  3. Once hosts that bind the toxin are known, build an affinity column to replace the C-18 column in the aquarium filter, and use this tool to collect the toxin for chemical characterization. This stationary phase could also be used for separating the toxins from other lipophilic components of the toxin extracts. The latter is a prerequisite for work on the biological aspects of these toxins. A large-scale application of this approach might be used in detoxification efforts.

Expected Results:

Purification and characterization of toxins from Pfiesteria piscicada, or similar organisms, should result from this investigation. Additionally, we hope to identify a fluorescent sensor molecule for the detection of these toxins in solution.

Publications and Presentations:

Publications have been submitted on this project: View all 9 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 3 journal articles for this project

Supplemental Keywords:

Pfiesteria toxins, harmful algal blooms, fluorescence sensing, combinatorial chemistry, RFA, Scientific Discipline, Geographic Area, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Limnology, Ecosystem/Assessment/Indicators, Ecosystem Protection, exploratory research environmental biology, Contaminated Sediments, Chemistry, State, Ecological Effects - Environmental Exposure & Risk, Ecological Effects - Human Health, algal blooms, Southeast, Biology, Ecological Indicators, East Coast, North Carolina, agricultural runoff, ecological exposure, pfiesteria piscicida, bloom dynamics, ecology, fish kills, suburban watersheds, Shephard's Crook, whole-fish bioassay, economic assessments, fish lesions, Gyrodiniums, harmful algal blooms, ligand sensitive hosts, Everglades, pfiesteria, environmental chemistry, toxins, bioassay, dinoflagellate, Glenodriniums, Tilapia, Florida, fluorescence sensing, Virginia, oceanography

Relevant Websites:

Progress and Final Reports:

  • 1999 Progress Report
  • 2000 Progress Report
  • 2001 Progress Report
  • Final Report