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 Scientists spin artificial silk from whey protein
24.01.2017 | Deutsches Elektronen-Synchrotron DESY

nachricht Choreographing the microRNA-target dance
24.01.2017 | UT Southwestern Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists spin artificial silk from whey protein

X-ray study throws light on key process for production

A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Breaking the optical bandwidth record of stable pulsed lasers

24.01.2017 | Physics and Astronomy

Choreographing the microRNA-target dance

24.01.2017 | Life Sciences

Spanish scientists create a 3-D bioprinter to print human skin

24.01.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>