Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Shedding Light on Bacteria

09.02.2016

The tiny cyanobacteria use the principle of the lens in the human eye to perceive light direction

Scientists have been trying to figure out how it is possible for bacteria to perceive light and react to it ever since they started using microscopes 300 years ago. An international team led by the Freiburg biologist Prof. Dr. Annegret Wilde has now solved this riddle: In studies on so-called cyanobacteria, the researchers demonstrated that these tiny organisms of only a few micrometers in size move toward a light source using the same principle of the lens in the human eye. The study was published in the journal eLife.


The light hits the round cells of the bacterium, where it is focused by a microscopically tiny lens. This creates a focal point on the opposite side of the cell. Source: Nils Schürgers

Cyanobacteria have populated Earth for 2.5 billion years and can be found anywhere where there’s light: in ice, deserts, rivers, and lakes, as well as in the walls of buildings and in aquariums. They use light to produce energy by the process of oxygenicphotosynthesis .

In the oceans, which cover roughly 70 percent of Earth’s surface, oxygen-producing cyanobacteria are among the most important photosynthetically active organisms and are thus a central component of the biosphere. The Wilde group together with an international team discovered that cyanobacteria, which can move directly and precisely toward a light source, use their micro-optic properties to identify where the light is coming from.

The light hits the surface of the round unicellular organisms, where it is focused as if by a microscopically tiny lens. This creates a focal point on the opposite side of the cell. The cells then move away from this point of high light intensity, causing them ultimately to move toward the natural light source.

All previous attempts to explain bacterial phototaxis, the process by which bacteria move toward light, have failed because these organisms, which measure only a few lengths of a light wave, were thought to be too small to perceive differences in light between the front and back side of the cell.

Since the entire bacterium functions like a lens, however, the organisms can concentrate light, creating a pronounced light gradient within the cell. “This physical principle is actually hardly different from the way light is focused in the lenses of our eyes,” explains Wilde. “We now want to conduct further joint projects to investigate the concentration of light in microscopic organisms that do not necessarily need to have the shape of a round lens but, for instance, can also concentrate light like an optical fiber.”

A better understanding of the microoptic properties could lead to insight on the extent to which the structure and form of cells and biofilms influence the process of light collection. This knowledge could be used in the future to construct custom-made photobioreactors or to improve new types of solar cells.

Annegret Wilde has served since 2012 as professor of molecular genetics at the University of Freiburg. The study included scientists from the Institute of Biology III as well as the university’s Freiburg Institute for Advanced Studies (FRIAS). The team collaborated strongly with researchers from Karlsruhe and London, England. A key participant in the study was Prof. Dr. Conrad Mullineaux from London who visited Freiburg as an FRIAS external fellow.

Original publication:
N. Schuergers, T. Lenn, R. Kampmann, M. V. Meissner, T. Esteves, M. Temerinac-Ott, J. G. Korvink, A. R. Lowe, C. W. Mullineaux, A. Wilde (2016): Cyanobacteria use micro-optics to sense light direction. In: eLife. DOI: 10.7554/eLife.12620

Contact:
Prof. Dr. Annegret Wilde
Institute of Biology III
University of Freiburg
Phone: +49 (0)761/203-97828
E-Mail: annegret.wilde@biologie.uni-freiburg.de

Caption:
The light hits the round cells of the bacterium, where it is focused by a microscopically tiny lens. This creates a focal point on the opposite side of the cell. Source: Nils Schürgers

Weitere Informationen:

http://www.pr.uni-freiburg.de/pm/2016/pm.2016-02-09.17-en?set_language=en

Rudolf-Werner Dreier | Albert-Ludwigs-Universität Freiburg im Breisgau

More articles from Life Sciences:

nachricht Closing the carbon loop
08.12.2016 | University of Pittsburgh

nachricht Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

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

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>