Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Discovery of algae's toxic hunting habits could help curb fish kills

22.01.2010
A microbe commonly found in the Chesapeake Bay and other waterways emits a poison not just to protect itself but to stun and immobilize the prey it plans to eat, a team of researchers from four universities has discovered. The findings about algae linked to massive fish kills could lead to new ways to slow the growth of these tiny but toxic marine creatures.

The researchers studied the behavior of the algal cell Karlodinium veneficum, known as a dinoflagellate and found in estuaries worldwide. Each year millions of dollars are spent on measures to control dinoflagellates around the globe. This particular species is known to release a substance called karlotoxin, which is extremely damaging to the gills of fish. Karlodinium veneficum has been known to form large algal blooms in the Chesapeake and elsewhere, triggering an immediate harmful impact on aquatic life, including fish kills.

"This new research opens the door to reducing bloom frequency and intensity by reducing the availability of its prey," said Allen Place of the Institute of Marine and Environmental Technology at the University of Maryland Center for Environmental Science. "As we reduce the nutrient load feeding Karlodinium's prey and bring back the bay's most prolific filter feeder, the Eastern oyster, we could essentially limit Karlodinium's ability to bloom."

Place, in whose laboratory karlotoxin was discovered and characterized, was a co-author of the new study, published this week in the online Early Edition of the Proceedings of the National Academy of Sciences. Other researchers involved in the study came from the University of Minnesota, The Johns Hopkins University and the University of Hawaii.

"This is a major environmental problem, but we didn't know why these microbes were producing the toxins in the first place," said Joseph Katz, the William F. Ward Sr. Professor in the Department of Mechanical Engineering at Johns Hopkins and a co-author of the paper. "Some people thought they were just using the toxins to scare away other predators and protect themselves. But with this new research, we've provided clear evidence that this species of K. veneficum is using the toxin to stun and capture its prey."

Historically, scientists have found it difficult to study the behavior of these tiny animals because the single-cell creatures can quickly swim out of a microscope's shallow field of focus. But in recent years this problem has been solved through the use of digital holographic microscopy, which can capture three-dimensional images of the troublesome microbes. The technique was pioneered by Katz.

In a study published in 2007, Katz, Place and Jian Sheng, who was Katz's doctoral student, were part of a team that reported the use of digital holographic microscopy to view the swimming behavior of K. veneficum and Pfiesteria piscicida. At the time, it appeared that K. veneficum slowed down into a "stealth mode" in order to ambush its prey while P. piscicida sped up to capture prey.

For the new paper, in which Sheng is lead author, the researchers used the same technique to more closely study the relationship between K. veneficum and its prey, a common, single-celled algal cell called a cryptophyte. They found that K. veneficum microbes release toxins to stun and immobilize their prey prior to ingestion, probably to increase the success rate of their hunt and to promote their growth.

This significantly shifts the understanding about what permits harmful algal blooms to form and grow, the researchers said. Instead of being a self-defense mechanism, the microbes' production of poison appears to be more closely related to growth through the ingestion of a "pre-packaged" food source, the cryptophyte cell, they concluded.

"In the paper, we have answered why these complicated [toxic] molecules are made in nature in the first place and identify a possible alternative mechanism causing massive bloom," said Sheng, who is now a faculty member in the University of Minnesota's Department of Aerospace Engineering and Mechanics.

Other co-authors of the PNAS paper are Edwin Malkiel, an adjunct associate research scientist in the Department of Mechanical Engineering at Johns Hopkins; and Jason E. Adolf, an assistant professor in the University of Hawaii's Department of Marine Science.

Funding for the research was provided by the National Science Foundation and the National Oceanic and Atmospheric Administration's Coastal Oceans Program.

The journal article maybe viewed online here: http://www.pnas.org/content/early/2010/01/14/0912254107.full.pdf+html.

Related links:
Joseph Katz's Web Page: http://web.jhu.edu/fluid_dynamics/index.html
Johns Hopkins Department of Mechanical Engineering: http://www.me.jhu.edu/
Jian Sheng's Web Page: http://www.aem.umn.edu/people/faculty/bio/jsheng.shtml
Allen Place's Web Page: http://www.umbi.umd.edu/comb/faculty-directory/place/

Phil Sneiderman | EurekAlert!
Further information:
http://www.jhu.edu

More articles from Life Sciences:

nachricht Scientists enlist engineered protein to battle the MERS virus
22.05.2017 | University of Toronto

nachricht Insight into enzyme's 3-D structure could cut biofuel costs
19.05.2017 | DOE/Los Alamos National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

Im Focus: Hydrogen Bonds Directly Detected for the First Time

For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.

Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

Media accreditation opens for historic year at European Health Forum Gastein

16.05.2017 | Event News

 
Latest News

New approach to revolutionize the production of molecular hydrogen

22.05.2017 | Materials Sciences

Scientists enlist engineered protein to battle the MERS virus

22.05.2017 | Life Sciences

Experts explain origins of topographic relief on Earth, Mars and Titan

22.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>