Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Living in a glass house: Ocean organism’s novel dwelling helps Earth’s atmosphere

19.09.2002


Why live in a glass house? For diatoms -- tiny ocean-dwelling organisms that live in exquisitely ornate glass cases -- the benefit turns out to be enormous.


Diatom



In a paper published in the Sept. 13 issue of Science, Princeton scientists show that diatoms probably depend on glass to survive because the material facilitates photosynthesis. However, their study suggests that this domestic arrangement has a much bigger beneficiary: the entire planet, which owes its present-day, oxygen-rich and carbon-poor atmosphere in part to diatoms and their effective use of glass.

Diatoms are one-celled organisms that are so prolific they account for a quarter of all the photosynthesis on the planet. In photosynthesis, organisms use sunlight and carbon dioxide to make sugar and oxygen.


"These guys proliferated at a time when atmospheric carbon dioxide took a big dive" 40 to 60 million years ago, said geochemist Allen Milligan, who conducted the study in collaboration with Francois Morel, director of the Princeton Environmental Institute.

The low carbon dioxide levels, while good for us today, posed a serious problem for plant life: how to perform photosynthesis when one of the raw ingredients is in short supply. Milligan and Morel found that diatoms solved the problem by encasing themselves in glass, which has chemical properties that help them concentrate carbon dioxide inside their vessels. With this device, diatoms flourished and now play an important role in keeping carbon dioxide levels low.

Diatoms have been a source of fascination since the first microscopes of the 1600s allowed scientists to sketch their intricate glass cases in pen and ink. The tough porous shells also have a variety of commercial uses. Swimming pool owners commonly use diatomaceous earth, which is rich with old diatom shells, to filter contaminants from pool water. In the 1860s, Alfred Nobel invented dynamite by using silica from diatoms to stabilize nitroglycerine into a portable stick.

"What we didn’t know was what good this glass wall is to the diatom itself," said Milligan.

According to Milligan and Morel’s study, the answer may have less to do with the structural properties that make diatoms useful to people than with the chemistry of silicon, a chief ingredient of glass. The researchers found that silica in the glass changes the acid-base chemistry of the water inside the shell, creating ideal conditions for one of the chemical reactions involved in photosynthesis.

By evolving this built-in reaction vessel, diatoms have had a tremendous impact, said Morel. "They are among the most successful organisms on earth."

The discovery is likely to be useful to scientists in a number of disciplines, said Morel, because it links two previously separate areas of research: the study of carbon and how it cycles through water, biological organisms and the atmosphere, and the study of silicon and how it cycles between water, diatoms and sediments.

Scientists who are trying to map past variations in the earth’s climate, for example, might use fossil records of diatoms and other indicators to infer how carbon dioxide concentration and diatom abundance have influenced each other at different points in the past. Having a firm grasp of such historical processes has become increasingly important as scientists try to predict the effects of greenhouse gas emissions, including carbon dioxide.

The study also offers an explanation for why diatom shells are so ornate. The many pores and filigrees create a lot of surface area, exposing much more glass to water than would be the case for a smooth structure. That extra surface area might make photosynthesis more efficient for the diatom. "These are very pretty things and their beauty might in fact be related to their function," said Morel.

Steven Schultz | EurekAlert!
Further information:
http://www.princeton.edu/

More articles from Life Sciences:

nachricht Toward a 'smart' patch that automatically delivers insulin when needed
18.01.2017 | American Chemical Society

nachricht 127 at one blow...
18.01.2017 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>