Navigation Links
Unknown ocean bacteria create entirely new theories

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 in the last week.

"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.


Contact: Siv Andersson
Uppsala University

Related biology news :

1. BIO 2009 -- R&D session: New stem cell research unlocks unknown therapies
2. Superscanner helps scientists see into the unknown
3. UCLA stem cell researchers uncover previously unknown patterns in DNA methylation
4. Ph.D. thesis describes 35 hitherto unknown families of endogenous retroviruses
5. Scientists and physicians use genetic sequencing to identify and treat unknown disease
6. Hair color of unknown offenders is no longer a secret
7. Unknown animals nearly invisible but yet there
8. Antarctic icebergs play a previously unknown role in global carbon cycle, climate
9. Jewel beetles, obtained from local people, turn out to be 4 species unknown to science
10. Watermark ink device identifies unknown liquids instantly
11. Diatom genome helps explain success in trapping excess carbon in oceans
Post Your Comments:
(Date:10/29/2015)... Calif. , Oct. 29, 2015  The J. ... new report titled, "DNA Synthesis and Biosecurity: Lessons Learned ... the Department of Health and Human Services guidance for ... in 2010. --> ... it also has the potential to pose unique biosecurity ...
(Date:10/29/2015)... , Oct. 29, 2015  Connected health pioneer, ... driving the explosion of technology-enabled health and wellness, and ... new book, The Internet of Healthy Things ... sensors or smartphones even existed, Dr. Kvedar, vice president, ... of health care delivery, moving care from the hospital ...
(Date:10/27/2015)... , Oct. 27, 2015 In the present ... of concern for various industry verticals such as banking, ... to the growing demand for secure & simplified access ... ,sectors, such as hacking of bank accounts, misuse of ... equipment such as PC,s, laptops, and smartphones are expected ...
Breaking Biology News(10 mins):
(Date:12/1/2015)... , Dec. 1, 2015  CardioCell LLC, a ... stem cells for cardiovascular indications, intends to proceed ... based on recommendations from a Heart Failure Advisory ... Scientific Advisory Board members . In a ... Phase IIa safety and efficacy data from CardioCell,s ...
(Date:12/1/2015)... ... December 01, 2015 , ... ... backed, age-defying products, is featured as the cover story and throughout Success ... unrivaled opportunities that Nerium provides. Success from Home magazine routinely features successful ...
(Date:12/1/2015)... -- Dr. Harry Lander , President of Regen, expands ... Science Officer and recruits five distinguished scientists to ... President of Regen, expands his role to include ... five distinguished scientists to join advisory team --> ... include serving as Chief Science Officer ...
(Date:12/1/2015)... , December 1, 2015 ... addition of the  "2016 U.K. Virology and ... Forecasts for 100 Tests, Supplier Shares by ...  report to their offering.  --> ... the  "2016 U.K. Virology and Bacteriology Testing ...
Breaking Biology Technology: