DDC Blog

Discovery Diving Co., Inc.
414 Orange St
Beaufort, North Carolina 28516
252-728-2265

dive@discoverydiving.com

The odor of stones

Diatoms are unicellular algae that are native in many waters. They are a major component of marine phytoplankton and the food base for a large variety of marine organisms. In addition, they produce about one fifth of the oxygen in the atmosphere and are therefore a key factor for our global climate. However, these algae, which measure only a few micrometers, have yet another amazing ability: they can "smell" stones.

 

"To be more precise, these algae are able to locate dissolved silicate minerals," Prof. Dr. Georg Pohnert, the chair of Instrumental Analytics at the Friedrich Schiller University in Jena, Germany, explains. A recent study by Pohnert and his research team published in the current issue of "Nature Communications" demonstrates that diatoms are not only able to trace silicate minerals in the water. Moreover, they can even move actively to areas where the concentration of silicates is especially high  (DOI: 10.1038/ncomms10540).

Algae need silicate for the structure of their strong mineral cell membranes, which are composed of two overlapping parts like a cardboard shoe box with a lid. During cell division, each of the two new cells receives one half of the box and regenerates the missing lid. "The algae have to search their environment for the building material," says Pohnert, who is also a Fellow at the Jena Max Planck Institute for Chemical Ecology.


Biofilms are constantly moving

For their study, the researchers from Jena and their colleagues from the University of Ghent, Belgium, observed and filmed Seminavis robusta diatoms under the microscope. The video shows what happens when algae are fed with a single silicate loaded granule: The tiny single-cell organisms, which grow in a biofilm on a solid surface, perform back and forth moves to approach the silicate source in the center of the screen and virtually "gobble it up". The algae are able to cover a distance of two micrometers per second, as shown in fast motion in the video. "It becomes obvious that diatom-dominated biofilms are actually constantly moving," Pohnert points out.

How the algae succeed in performing a target-oriented movement remains to be elucidated yet. "We do currently not know, which receptors the algae have or which mechanisms mediate the perception," says Karen Grace Bondoc from Pohnert's research team. The PhD student, who is a fellow of the International Max Planck Research School "Exploration of Ecological Interactions with Molecular and Chemical Techniques", is the first author of the publication. In her PhD project she studies complex interactions of the organisms in marine biofilms.

Surfaces and materials free of algea

However, the scientists showed that the diatoms were solely attracted by the odor of the silicate. If the researchers replaced the silicate mineral with structurally similar salts containing Germanium which is toxic to the algae, the algae moved away from the mineral source. Even though the experiments are pure basic research, the Jena chemists see the potential for practical application in the long term. "If we understand the processes that make the algae colonize one particular area or avoid other regions, we could use this information to selectively design surfaces and materials in such a way that they stay free of algae," Pohnert emphasizes. Such materials could be used for the hulls of ships or water pipes which are often damaged by algal colonization. 

 

Original Publication:
Bondoc, K. G., Heuschele, J., Gillard, J., Vyverman, W., Pohnert, G. (2016). Selective silica-directed motility in diatoms. Nature Communications. DOI: 10.1038/ncomms10540

Uncovering the USS Macon: The Underwater Airship
Killer Robots Slash Jellyfish
 

Comments

Already Registered? Login Here
No comments made yet. Be the first to submit a comment

U/W Bike Race

eventsiconJoin us on July 4th for this annual event benefitting the Children's Mile of Hope.

Lionfish Tournament

eventsiconWe need your help to make Carteret County's 6th Annual "If you Can't Beat 'em, Eat 'em" Spearfishing Tournament a success! This Tournament is a joint effort between Discovery Diving and Eastern Carolina Artificial Reef Association (ECARA).

Treasure Hunt

eventsiconFood, prizes, diving, and fun! Proceeds benefit the Mile Hope Children's Cancer Fund and DAN's research in diving safety.

ECARA Event

2013Join us in support of the East Carolina Artificial Reef Association.  Click here for more info on this great event and how you can help to bring more Wrecks to the Graveyard of the Atlantic.