[D66] Chemists reveal how algae delete unwanted 'competitors'

[Henk Elegeert]

Chemists reveal how algae delete unwanted 'competitors'

January 30, 2012 <http://www.physorg.com/archive/30-01-2012/>

[image: Chemists reveal how algae delete unwanted 'competitors']The chemist
Professor Dr. Georg Pohnert of Jena University checks cultures of algae
kept in a special container. Credit: Photo: Jan-Peter Kasper/Univ. Jena

Every morning when the sun comes up, the ocean ground is radically cleaned.
As soon as the first rays of sunlight find their way into the water, the
microalgae "Nitzschia cf pellucida" start their deadly 'morning hygiene'.
The algae, the size of only some few micrometers, wrap themselves and their
surroundings in a highly toxic poison: cyanogen bromide, a chemical
relative of hydrocyanic acid, although much more toxic.

Like a 'molecular toothbrush', which removes other
micro-organisms<http://www.physorg.com/tags/micro+organisms/>thoroughly,
every morning this chemical mace 'disinfects' the ground on which these
diatoms grow. "Thus they can ideally grow and keep direct competitors for
light and free space in check," Professor Dr. Georg Pohnert of the
Friedrich Schiller University Jena (Germany) states. The director of the
Institute of Inorganic and Analytical
Chemistry<http://www.physorg.com/tags/analytical+chemistry/>revealed
together with his team and colleagues of the University Ghent
(Belgium) the chemical devastating blow of the diatoms. Their findings were
published in the new edition of the well known science magazine *Proceedings
of the National Academy of
Sciences*<http://www.physorg.com/tags/proceedings+of+the+national+academy+of+sciences/>
.

Cyanogen bromide is a highly poisonous metabolic toxin and is – amongst
other things – being used for the lixiviating of gold ores. During the
First World War it was also used as a chemical weapon. "Until now it wasn't
even known that this poison occurs in the living nature at all," says
Professor Pohnert. For "Nitzschia cf pellucida" the production of cyanogen
bromide seems to be easy though. As soon as the first rays of sunlight find
their way into the water, the cellular 'devil's workshop' starts to work.
"From two up to four hours after day break the concentration of the
released cyanogen bromide is at its highest, later on it decreases,"
Professor Pohnert explains one of the results of his new study.

The scientists can still only speculate about the fact that the poison
doesn't harm the diatoms themselves. One thing is for sure: While the
'competing' algae give up after two hours at most, subsequent to being
attacked by cyanogen bromide the poison at the same time doesn't harm
Nitzschia cf pellucida. To find the reasons for this is one of the next
research objectives of the Jena scientists and their Belgian partners.

But according to chemist Pohnert this would be pure basic research.
Cyanogen bromide is completely inapplicable to practical use – for instance
as a means against unwanted algae growth. Because it is certain that in
this case it is not only the algae
<http://www.physorg.com/tags/algae/>that would be damaged.

*More information:* Vanelslander B et al.: Daily bursts of biogenic
cyanogen bromide (BrCN) control biofilm formation around a marine benthic
diatom.

*PNAS *2012, *doi:10.1073/pnas.1108062109<http://dx.doi.org/10.1073/pnas.1108062109>
*

Provided by Friedrich-Schiller-Universitaet Jena

"

... met verstrekkende gevolgen voor het 'klimaat'?

Henk Elegeert
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