Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Odd energy mechanism in bacteria analyzed

07.11.2005


Scientists at Oregon State University have successfully cultured in a laboratory a microorganism with a gene for an alternate form of photochemistry – an advance that may ultimately help shed light on the ecology of the world’s oceans.



The microorganism is SAR11, the smallest free living cell known and probably the most abundant organism in the seas. By being able for the first time to study the SAR11 "proteorhodopsin" gene in a laboratory, researchers will be able to better understand how it is activated, its role in the life and survival of SAR11, and how it affects ocean ecology. The findings are being published today in the journal Nature.

Surprisingly, the SAR11 bacteria continued to grow normally whether or not there was light available - indicating to OSU researchers that the cell does not require this energy producing mechanism in normal conditions. It’s possible, they said, that this alternate form of photochemistry serves as a "backup" system to provide energy to the cells when they face starvation in the open ocean, which often has very limited nutrients.


"It’s exciting to learn more about another form of photochemistry that does not use chlorophyll", said Stephen Giovannoni, a professor of microbiology at OSU. "This proteorhodopsin gene, however, seems to have a subtle role in the life and survival of SAR11, and appears to be an auxiliary system to aid cell survival."

The level of interest in SAR11 is high, researchers say, because it dominates microbial life in the oceans, survives where most other cells would die, and plays a major role in the cycling of carbon on Earth. These bacteria may have been thriving for a billion years or more, but they have the smallest genetic structure of any independent cell and were only first discovered by OSU scientists in 1990.

Although tiny, because of their huge numbers SAR11 plays a major role in the planet’s carbon cycle as a consumer of organic carbon. Its main energy generating system is the respiration of organic carbon, producing carbon dioxide and water in the process.

Oxygen in the Earth’s atmosphere was largely created and is maintained by photosynthesis, in which plants convert sunlight into biological energy through a process that requires chlorophyll. In the oceans, SAR11 is a partner in this process, recycling organic carbon and producing the nutrients needed for the algae that produce about half of the oxygen that enters Earth’s atmosphere every day.

The carbon cycle ultimately affects all plant and animal life on Earth.

However, it’s now clear that SAR11 has its own mechanism to use sunlight energy that does not involve chlorophyll. Rather, it uses retinal, the same protein used by the eyes of animals and humans to detect light, and serves as a "proton pump" to energize the cell membrane. Proteorhodopsin was only discovered in 2000, but until now, it had not been found in a living organism. It’s still not totally clear, Giovannoni said, how this energy producing mechanism benefits the cell.

"When we turned the lights off, there was no mechanism for the proteorhodopsin gene to produce energy, but that didn’t seem to make any difference in the growth rate of SAR11," Giovannoni said. "So we know that under normal conditions this alternate form of energy production is not required. This system may be there for emergencies. But it may still be very important to ocean life, and that’s what we need to find out more about."

Steve Giovannoni | EurekAlert!
Further information:
http://www.oregonstate.edu

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>