Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Purple bacteria on Earth could survive alien light

University of Miami researchers show that extreme alien light could support life of terrestrial bacteria

Purple bacteria contain pigments that allow them to use sunlight as their source of energy, hence their color. Small as they are, these microbes can teach us a lot about life on Earth, because they have been around longer than most other organisms on the planet.

Purple bacteria make a "gel" around the individual cells which binds them into a colony. That is why they appear as "clouds." The insert illustrates the general principle of the model used in the study. It depicts photons arriving, then being passed around the bacteria's membrane, where the light harvesting mechanism is located, then arriving at the various reaction center 'kitchens', being processed, and then being turned out as metabolic products for the bacteria to survive.

Credit: Dr. Wayne B. Lanier

University of Miami (UM) physicist Neil Johnson, who studies purple bacteria, recently found that these organisms can also survive in the presence of extreme alien light. The findings show that the way in which light is received by the bacteria can dictate the difference between life and death.

Johnson, head of the inter-disciplinary research group in complexity in the College of Arts and Sciences at UM and his collaborators share their findings in a paper titled "Extreme alien light allows survival of terrestrial bacteria" published online in Nature's Scientific Reports. The study reveals new possibilities for life on earth and elsewhere in the universe.

"The novelty of our work is that despite all the effort aimed at finding planets outside our solar system where life might exist, people have ignored the fact that photosynthesis--and hence life on Earth-- isn't just about having the right atmosphere and light intensity," Johnson says. "Instead, as we show, a crucial missing ingredient is how the light arrives at the organism."

The results are also applicable in the scenario of our own sun developing extreme fluctuations and in a situation in which bacteria are subject to extreme artificial light sources in the laboratory.

The findings may also help with engineering a new generation of designer-light-harvesting structures.

Using a mathematical model the researchers calculated the probability of survival when the bacteria is subjected to bursts of light, similar to what might be experienced if the light source was an unstable star. The flow of light was on average the same as the bacteria would normally receive, but since they would be receiving it in such a strange way, the researchers wondered under what situations the bacteria could survive.

"It's like saying we know we need to bring home a certain amount of food per week, but what happens if all of the food is delivered in one day? You might not be able to store all of it," Johnson says. "Maybe some food would get spoiled, or maybe you wouldn't have time to use it all," he says. "The light is like food for the bacteria, and the issue is the amount of food and the timing with which you bring it in."

Light comes in packets of photons. Purple bacteria process light in places callereaction centers, where the energy of the photons fuels the production of metabolic materials. Johnson compares the situation to asking what happens when food arrives in the kitchen in an irregular way.

"The reaction center, like any kitchen, can't do a thousand things at once. They can only handle one photon at a time," Johnson says. "The new chemicals made in the process take some time to diffuse. Otherwise, it results in a buildup of chemicals that can kill the bacteria," he says. "Since we are concluding this from statistical calculations, we can say it's very unlikely that the bacteria will survive."

To their surprise, the researchers found that while many seemingly innocuous changes in the way the light arrives at the organisms end up proving fatal, the bacteria could survive a sudden deluge of photons. The key to enduring such extreme conditions is that that there are many reaction center 'kitchens.' Therefore, the photons spread out naturally, leaving each reaction center enough time to recover.

"Ultimately the chemicals have time to diffuse and that is what saves it," Johnson says. "On the average the bacteria is therefore getting what it needs from the reaction centers."

The researchers suspect this mechanism is not unique to purple bacteria. In the future, they will expand the study to other photosynthetic life forms.

Co-authors of the study are Guannan Zhao, who was a postdoctoral fellow at UM at the time of the project; Pedro Manrique and Hong Qi doctoral students at UM; Felipe Caycedo, postdoctoral fellow at Universitat Ulm, Germany; Ferney Rodriguez and Luis Quiroga, professors at Universidad de Los Andes, Bogota, Colombia.

The University of Miami's mission is to educate and nurture students, to create knowledge, and to provide service to our community and beyond. Committed to excellence and proud of our diversity of our University family, we strive to develop future leaders of our nation and the world.

Annette Gallagher | 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

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>