Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Diatom genome reveals key role in biosphere’s carbon cycle

04.10.2004


The first genetic instruction manual of a diatom, from a family of microscopic ocean algae that are among the Earth’s most prolific carbon dioxide assimilators, has yielded important insights on how the creature uses nitrogen, fats, and silica to thrive.



The diatom DNA sequencing project, funded by the U.S. Department of Energy (DOE) and conducted at the DOE Joint Genome Institute, provides insight into how the diatom species Thalassiosira pseudonana prospers in the marine environment while it contributes to absorbing the major greenhouse gas CO2,in amounts comparable to all the world’s tropical rain forests combined. "This critical information enables us to better understand the vital role that diatoms and other phytoplankton play in mediating global warming," says Dan Rokhsar, who heads computational genomics at the JGI and is one of the co-authors of a research article in the Oct. 1 issue of Science. "Now that we have a glimpse at the inner workings of diatoms, we’re better positioned to understand how changes in their population numbers will translate into environmental changes and the global carbon management picture."

"These organisms are incredibly important in the global carbon cycle," says Virginia Armbrust, a University of Washington associate professor of oceanography and lead author of the Science paper. Together, the single-celled organisms generate as much as 40 percent of the 50 billion to 55 billion tons of organic carbon produced each year in the sea and in the process use carbon dioxide and produce oxygen. And they are an important food source for many other marine organisms.


Scientists would like to better understand how these organisms react to changes in sea temperatures, the amount of light penetrating the oceans, and nutrients. "Oceanographers thought we understood how diatoms use nitrogen, but we discovered they have a urea cycle, something no one ever suspected," Armbrust says. A urea cycle is a nitrogen waste pathway found in animals and has never before been seen in a photosynthetic eukaryote like a diatom, she says. Nitrogen is crucial for diatom growth and is often in short supply in seawater, depending on ocean conditions. The genome work revealed that the diatom Thalassiosira pseudonana has the genes to produce urea-cycle enzymes that may help to reduce its dependence on nitrogen from the surrounding waters.

The genome work also shed additional light on how this diatom species uses fats, or lipids, which it is known to store in huge amounts. "Learning the actual pathways they use to metabolize their fats helps explain the ability of diatoms to withstand long periods with little sunlight--even to overwinter--and then start growing really rapidly once they return to sunlight," she says.

Three or four microns in width--as many as 70 could fit in the width of a human hair--Thalassiosira pseudonana is among the smallest diatoms. Like its brethren, it is encased by a frustule, a rigid cell wall delicately marked with pores in patterns distinctive enough for scientists to tell the species apart. Another new finding reported in Science concerns the unusual way the diatom metabolizes silicon to form its characteristically ornate silica frustule. "Diatoms can manipulate silica in ways that nanotechnologists can only dream about. If we understood how they can design and build their patterned frustule as part of their biology, perhaps this could be adapted by humans," Rokhsar says.

Scientists on the project, which includes 46 researchers from 26 institutions, also considered the evolutionary implications revealed by the genomic work. The research provided direct genetic confirmation of a hypothesis that diatoms evolved when a heterotroph, a single-cell microbe, engulfed what scientists say was likely a kind of red alga. The two became one organism, an arrangement called endosymbiosis, and swapped some genetic material to create a new hybrid genome.

"This project helps illustrate the amazing diversity of life on our planet," Armbrust says. "Diatoms display features traditionally thought to be restricted to animals and other features thought to be restricted to plants. Diatoms, with complete disregard for these presumed boundaries, have mixed and matched different attributes to create an incredibly successful microorganism. It’s exciting to imagine the novelty in the oceans that still awaits our discovery."

David Gilbert | EurekAlert!
Further information:
http://www.lbl.gov
http://www.jgi.doe.gov

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

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

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>