Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Algae toxin identification unravels fish-kill mystery

23.01.2007
A team of researchers from the Hollings Marine Laboratory in Charleston, S.C., has uncovered a subtle chemical pathway by which a normally inoffensive algae, Pfiesteria piscicida, can suddenly start producing a lethal toxin.

The discovery, reported last week in Environmental Science and Technology,* could resolve a long-standing mystery surrounding occasional mass fish kills on the East Coast.

Pfiesteria has been implicated for years in a series of otherwise unexplained episodes of mass fish death throughout its range from roughly Delaware to Alabama, particularly in the Neuse River in North Carolina and the Chesapeake Bay. The single-cell organism can experience explosive growth resulting in algae blooms in coastal waters. While it has been suspected not only in fish kills but in incidents of human memory loss and other environmental and health-related effects, no one has ever conclusively identified the actual mechanism.

Attempts to grow lethal Pfiesteria in the laboratory have had inconsistent results.

The Hollings Marine Laboratory is a joint institution of the National Oceanic and Atmospheric Administration (NOAA), the National Institute of Standards and Technology (NIST), the South Carolina Department of Natural Resources, the College of Charleston, and the Medical University of South Carolina (MUSC). Lead researcher Peter Moeller of NOAA suspected that the presence or absence of heavy metals might be the missing factor accounting for Pfiesteria's lethality, and put together a multidisciplinary research team to identify the actual toxin and the conditions under which it is produced.

The work was complicated by the fact that the suspect toxin turns out to be highly unstable, decomposing rapidly once it's activated. Chemists from NIST and MUSC used an array of advanced spectroscopic techniques to determine that the toxin is characterized by the presence of copper-sulfur complexes. "NIST saved the day," Moeller said, "because we were working with only microgram and submicrogram quantities of the toxin. To not only determine that a metal was indeed present but even tell us which one really broke things open."

With that lead, Moeller's team established that the Pfiesteria cell can produce a copper-containing exotoxin--a toxin produced external to the cell itself--possibly as a mechanism to protect itself from copper in the environment. When exposed to sunlight or other environmental factors that can destabilize it, the toxin rapidly breaks down into short-lived free radicals, highly reactive chemical species believed to be the actual lethal agents. To observe the entire chain of events requires just the right combination of copper ions, temperature, light and Pfiesteria, explaining the difficulty researchers have had in reproducing the effect according to Moeller.

Although exotoxins like that produced by Pfiesteria are not common, the researchers observe, a number of other microalgae species are known to produce them, and under the right conditions in metal-rich waters they also might produce lethal variants.

Michael Baum | EurekAlert!
Further information:
http://www.nist.gov

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Decoding the structure of the huntingtin protein

22.02.2018 | Life Sciences

Camera technology in vehicles: Low-latency image data compression

22.02.2018 | Information Technology

Minimising risks of transplants

22.02.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>