Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Odd energy mechanism in bacteria analyzed


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:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Novel mechanisms of action discovered for the skin cancer medication Imiquimod

21.10.2016 | Life Sciences

Second research flight into zero gravity

21.10.2016 | Life Sciences

How Does Friendly Fire Happen in the Pancreas?

21.10.2016 | Life Sciences

More VideoLinks >>>