. Earth Science News .

Unknown ocean bacteria create entirely new theories
by Staff Writers
Uppsala, Sweden (SPX) Sep 20, 2011

File image.

The earth's most successful bacteria are found in the oceans and belong to the group SAR11. In a new study, researchers from Uppsala University provide an explanation for their success and at the same time call into question generally accepted theories about these bacteria. In their analysis they have also identified a rare and hitherto unknown relative of mitochondria, the power stations inside cells.

The findings were published in two articles in the journals Molecular Biology and Evolution and PLoS One.

"The huge amounts of DNA information now being produced from the oceans gives us a glimpse of a world that could never be studied before. It's incredibly fascinating to look for answers to the fundamental questions of life in these data, says Siv Andersson, professor of molecular evolution and lead author of the studies.

Bacteria belonging to the group SAR11 make up 30-40 percent of all bacteria cells in the oceans and therefore play a considerable role in global carbon cycles. Nowhere else are these bacteria so common. The open seas are poor in nutrients, and SAR11 bacteria have an extremely small cell volume in order to maximize the concentration of nutrients in the cells. Their genomes are small, consisting of fewer than 1.5 million building blocks.

According to previous research they are related to an equally specialized group of bacteria that includes the typhus bacterium. These bacteria also have small genomes, but they are adapted to humans, animals, and insects.

However, the advanced analyses of evolutionary relationships performed by the Uppsala researchers contradict these findings, indicating instead that SAR11 bacteria evolved from ocean- and earth-dwelling bacteria with genomes that are three to ten times as large.

But unlike their closest relatives, SAR11 bacteria lack genes that are thought to be important in repairing damage to DNA. This might also explain why they have been so successful.

"The loss of genes means that the bacteria can more readily exchange genes with each other, and beneficial genes can then spread rapidly in the oceans as an adaptation to changes in nutrient content, temperature, and UV radiation, says Johan Viklund, a doctoral candidate at the Department of Molecular Evolution.

By digging into the data produced by ongoing international surveys of DNA from all the bacteria in the oceans, the Uppsala scientists have also found DNA sequences for proteins that participate in cell respiration, when sugar is broken down into carbon dioxide and water.

By comparing these with the corresponding proteins for cell respiration in the so-called mitochondria of humans, animals, and insects, the researchers managed to identify a rare, previously unknown group of bacteria.

"These bacteria are very similar to mitochondria. Our findings thus indicate that the origin of mitochondria might be the oceans, but that the closest relatives are not related to the SAR11 group as was previously thought, says Thijs Ettema, a postdoctoral fellow with the team.

Read the full article in PLoS

Related Links
Uppsala University
Water News - Science, Technology and Politics


Get Our Free Newsletters Via Email
Buy Advertising Editorial Enquiries

. Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

European fish stocks changing with warming seas
Bristol UK (SPX) Sep 20, 2011
The first "big picture" study of the effects of rapidly rising temperatures in the northeast Atlantic Ocean shows that a major shift in fish stocks is already well underway. But it isn't all bad news. The research, published in Current Biology, shows that some fishes' losses are other fishes' gain. The study led by Dr Steve Simpson of the University of Bristol in collaboration with researc ... read more

S. Korea court rejects bid to shut nuclear reactor

Goalposts and blankets comfort quake survivors

China punishes officials over deadly explosions

Tsunami protection wall for Japan atomic plant

New technology for recovering valuable minerals from waste rock

3D television without glasses

Personalised 3D avatars for real life

Google opening smartphone wallets

Plants create a water reserve in the soil

Study: Oceans can level global warming

Unknown ocean bacteria create entirely new theories

Salmon and other fish predators rely on 'no guts, no glory' survival tactic

Arctic sea ice reaches minimum 2011 extent

Row over British atlas showing greener Greenland

A Coral Reef in the Arctic

Arctic ice at 2nd lowest level since 1979: US report

Breeding Soybeans for Improved Feed

Restoring forests and planting trees on farms can greatly improve food security

China reporter killed after 'gutter' oil news

Consumers willing to pay premium for healthier genetically modified foods

Sikkim: Himalayan paradise at quake epicentre

Mass evacuations as China flood deaths rise to 70

Italian scientists go on trial over 2009 earthquake

Himalayan quake rescuers blast route to epicentre

China to build $439-million housing complex in Mozambique

Niger seeks help over Libya arms fallout

No US-China arms sales race in Africa: US general

CIA boosts covert operations in Somalia

Serotonin levels affect the brain's response to anger

Self-delusion is a winning survival strategy

Study suggests methylation and gene sequence co-evolve in human-chimp evolutionary divergence

Researchers Utilize Neuroimaging To Show How Brain Uses Objects to Recognize Scenes

Memory Foam Mattress Review
Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2011 - Space Media Network. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement