Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Corals turn to algae for stored food when times get tough

14.05.2013
Researchers at EPFL present new evidence for the crucial role of algae in the survival of their coral hosts. Ultra-high resolution images reveal that the algae temporarily store nutrients as crystals, building up reserves for when supplies run low

Researchers at EPFL present new evidence for the crucial role of algae in the survival of their coral hosts. Ultra-high resolution images reveal that the algae temporarily store nutrients as crystals, building up reserves for when supplies run low.

The relationship between corals and the microscopic algae they harbor is a classic example of biological symbiosis - the mutually beneficial interaction of two species. But crucial details regarding their relationship have remained elusive until now. Using state-of-the-art imaging techniques, Anders Meibom and his team of researchers in the Laboratory for Biological Geochemistry have found new evidence on the vital role algae play in helping corals survive in environments where nutrients are scarce. Their findings were published in the journal mBio on May 16, 2013.

"Coral reefs are the jungles of our oceans - hotspots of biodiversity that easily outcompete all other marine ecosystems," says Christophe Kopp, first-author of the publication. Coral bleaching occurs when the colorful algae abandon their coral host because of environmental strains like rising sea temperatures. On their own, corals struggle to survive in tropical waters where nutrients are scarce, and persistent starvation can have irreversible effects. While it is well known that algae help corals to assimilate certain nutrients, such as nitrogen from seawater, how this occurs, and to what extent the corals can get by on their own, are less clear.

To study how nitrogen-rich nutrients are taken up and processed by the corals and the algae that inhabit them, Meibom's research group teamed up with the Aquarium Tropicale Porte Dorée in Paris to run a series of experiments. There, they fed the corals nitrogen-rich compounds labeled with a heavy nitrogen isotope that they could later trace in the lab. Every few minutes, they extracted bits of coral, which they fixed and analyzed with a state-of-the-art isotopic imaging instrument, a so-called NanoSIMS.

Next, they assembled a timeline of how the nitrogen is processed by the corals and their resident algae by lining up the images of the samples extracted at different times. A combination of electron microscopy and mass spectrometry allowed them to study with unprecedented precision into which cellular compartments the heavier nitrogen isotopes had been incorporated.

Crystal food banks

The research revealed that the corals depend strongly on the algae to extract sufficient nutrients from the water. This was particularly true when the corals were exposed to nitrate, a compound that they are unable to process and assimilate on their own.

But most interestingly, the scientists observed that the algae act as tiny food banks. Their images revealed that the algae temporarily store the nitrogen in the form of uric acid crystals – a fact they later confirmed using crystallographic analysis. This way, the algae can stock up on nutrients when supply is abundant and draw on them when supply drops, leaching some out to their coral host.

Because coral reefs are at the foundation of immense economic activity, both as tourist magnets and as the habitats of some of the most productive fish populations, understanding their fate as the environment they inhabit changes is not only of ecological, but also of economic importance.

The research was performed in close collaboration with EPFL's Interdisciplinary Centre For Electron Microscopy (CIME), the Institute of Earth Science at the University of Lausanne, as well as the Aquarium Tropicale Porte Dorée and the Muséum d'Histoire Naturelle in Paris. The work is funded by an ERC Advanced grant and by a grant from the Swiss National Science Foundation.

Anders Meibom | EurekAlert!
Further information:
http://www.epfl.ch

More articles from Life Sciences:

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

nachricht Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>