Navigation Links
Microbe has huge role in ocean life, carbon cycle

Researchers at Oregon State University and Diversa Corporation have discovered that the smallest free-living cell known also has the smallest genome, or genetic structure, of any independent cell - and yet it dominates life in the oceans, thrives where most other cells would die, and plays a huge role in the cycling of carbon on Earth.

In nature, apparently, bigger is not always better.

In a publication today in the journal Science, scientists outlined the growing knowledge about SAR11, a group of bacteria so dominant that their combined weight exceeds that of all the fish in the world's oceans. In a marine environment that's low in nutrients and other resources, they are able to survive and replicate in extraordinary numbers ?a milliliter of sea water off the Oregon coast might contain 500,000 of these cells.

"The ocean is a very competitive environment, and these bacteria apparently won the race," said Stephen Giovannoni, an OSU professor of microbiology. "Our analysis of the SAR11 genome indicates that they became the dominant life form in the oceans largely by being the simplest."

The new study outlines how SAR11 has one of the most compact, streamlined genomes ever discovered, with only 1.3 million base pairs ?the smallest ever found in a free living organism and a number that's literally tiny compared to something like the human genome.

"SAR11 has almost no wasted DNA," Giovannoni said. "This organism is extremely small and efficient. Every genetic part serves a purpose, more so than any other genome we've studied."

The organism is able to survive as an unattached cell in a hostile environment, has a complete set of biosynthetic pathways, and can reproduce efficiently by consuming dissolved organic matter.

"By comparison, humans are mostly junk DNA, with large parts of the human genome having no important function," Giovannoni said.

This type of genome streamlining, researchers say, appears to be a major factor in the evolutionary success of SAR11, which they believe may have been thriving for a billion years or more. One scientific hypothesis holds that natural selection acts to reduce genome size because of the metabolic burden of replicating "junk" DNA with no adaptive value - SAR11 supports that theory.

Researchers are particularly interested in SAR11, Giovannoni said, because of the critical role it plays in geochemistry. Photosynthesis is a process used by plants to convert sunlight energy into organic molecules, creating the foundation of the food chain and producing oxygen. About half of photosynthesis and the resulting oxygen on Earth are produced by algae in the ocean, and microbes like SAR11 recycle organic carbon - producing the nutrients needed for algal growth.

"Ultimately, SAR11 through its sheer abundance plays a major role in the Earth's carbon cycle," Giovannoni said. "Quite simply, this is something we need to know more about. SAR11 is a major consumer of the organic carbon in the oceans, which nearly equals the amount of carbon dioxide in the atmosphere. The carbon cycle affects all forms of plant and animal life, not to mention the atmosphere and fossil fuel formation."

SAR11 was first discovered at OSU in 1990. Since then researchers have learned that populations of SAR11 increase during the summer and decrease during the winter, in a cycle that correlates to the ebb and flow of organic carbon in the ocean surface. Molecular probes, gene cloning, sequencing techniques and other tools have been used in this exploration.


'"/>

Source:Oregon State University


Related biology news :

1. Researchers Discover That Microbes Can Produce Miniature Electrical Wires
2. Microbes under Greenland Ice may be preview of what scientists find under Mars surface
3. Microbes convert Styrofoam? into biodegradable plastic
4. Microbes hitchhike across Atlantic on desert dust
5. Microbes transform safest PBDEs into more harmful compounds
6. Microbe fixes nitrogen at a blistering 92 C
7. Microbes compete with animals for food by making it stink
8. Microbes start immune response by sneaking inside cells
9. NASA study finds snow melt causes large ocean plant blooms
10. Anammox bacteria produce nitrogen gas in oceans snackbar
11. Elephant seal pups suffer from ocean warming
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/13/2017)... April 13, 2017 UBM,s Advanced Design and ... will feature emerging and evolving technology through its 3D ... will run alongside the expo portion of the event ... and demonstrations focused on trending topics within 3D printing ... and manufacturing event will take place June 13-15, 2017 at ...
(Date:4/11/2017)... Research and Markets has announced the addition of the ... ... grow at a CAGR of 30.37% during the period 2017-2021. ... prepared based on an in-depth market analysis with inputs from industry ... over the coming years. The report also includes a discussion of ...
(Date:4/6/2017)... April 6, 2017 Forecasts by ... Document Readers, by End-Use (Transportation & Logistics, Government & ... Gas & Fossil Generation Facility, Nuclear Power), Industrial, Retail, ... Are you looking for a definitive report ... ...
Breaking Biology News(10 mins):
(Date:7/17/2017)... ... 2017 , ... DuPont Pioneer today announced the launch of ... dedicated to connecting third-party innovators with DuPont Pioneer scientists is now available and ... and digital solutions. , “DuPont Pioneer is building on its long history of ...
(Date:7/14/2017)... ... 14, 2017 , ... Sonic Manufacturing Technologies is proud to ... a solar system on its roof top. “We will be independent of the ... Raab stated. The company’s proud history of social responsibility and participation in the ...
(Date:7/13/2017)... , ... July 13, 2017 , ... Thousands of pilots ... August for the National Aeromodeling Championships (Nats). Pilots come to Muncie to compete in ... earn spots on US teams that participate in world championships. , RC Pylon (July ...
(Date:7/13/2017)... ... July 13, 2017 , ... Frederick’s first and only ... growth in the past year after an intensive restructuring. Under the leadership of ... and expanded its board of directors to revitalize the organization. As a result, ...
Breaking Biology Technology: