Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists Show Bacteria Can Plan Ahead

19.06.2009
Bacteria can anticipate a future event and prepare for it, according to new research at the Weizmann Institute of Science.

In a paper that appeared in the June 17, 2009 issue of Nature, Prof. Yitzhak Pilpel, doctoral student Amir Mitchell, and research associate Dr. Orna Dahan of the Institute’s Molecular Genetics Department, together with Prof. Martin Kupiec and Gal Romano of Tel Aviv University, examined microorganisms living in environments that change in predictable ways. Their findings show that these microorganisms’ genetic networks are hard-wired to “foresee” what comes next in the sequence of events and begin responding to the new state of affairs before its onset.

E. coli bacteria, for instance, which normally cruise harmlessly down the digestive tract, encounter a number of different environments on their way. In particular, they find that one type of sugar – lactose – is invariably followed by a second sugar – maltose – soon afterward. Pilpel and his team in the Molecular Genetics Department checked the bacteria’s genetic response to lactose and found that, in addition to the genes that enable it to digest lactose, the gene network for utilizing maltose was partially activated. When they switched the order of the sugars, giving the bacteria maltose first, there was no corresponding activation of lactose genes, implying that bacteria have naturally “learned” to get ready for a serving of maltose after a lactose appetizer.

Another microorganism that experiences consistent changes is wine yeast. As fermentation progresses, sugar and acidity levels change, alcohol levels rise, and the yeast’s environment heats up. Although the system was somewhat more complicated than that of E. coli, the scientists found that when the wine yeast feel the heat, they begin activating genes for dealing with the stresses of the next stage. Further analysis showed that this anticipation and early response is an evolutionary adaptation that increases the organism’s chances of survival.

Ivan Pavlov first demonstrated this type of adaptive anticipation, known as a conditioned response, in dogs in the 1890s. He trained the dogs to salivate in response to a stimulus by repeatedly ringing a bell before giving them food. In the microorganisms, says Pilpel, “evolution over many generations replaces conditioned learning, but the end result is similar.” “In both evolution and learning,” says Mitchell, “the organism adapts its responses to environmental cues, improving its ability to survive.” Romano: “This is not a generalized stress response, but one that is precisely geared to an anticipated event.” To see whether the microorganisms were truly exhibiting a conditioned response, Pilpel and Mitchell devised a further test for the E. coli based on another of Pavlov’s experiments. When Pavlov stopped giving the dogs food after ringing the bell, the conditioned response faded until they eventually ceased salivating at its sound. The scientists did something similar, using bacteria grown by Dr. Erez Dekel, in the lab of Prof. Uri Alon of the Weizmann Institute’s Molecular Cell Biology Department, in an environment containing the first sugar, lactose, but not following it up with maltose. After several months, the bacteria had evolved to stop activating their maltose genes at the taste of lactose, only turning them on when maltose was actually available.

“This showed us that there is a cost to advanced preparation, but that the benefits to the organism outweigh the costs in the right circumstances,” says Pilpel. What are those circumstances? Based on the experimental evidence, the research team created a sort of cost/benefit model to predict the types of situations in which an organism could increase its chances of survival by evolving to anticipate future events. The researchers are already planning a number of new tests for their model, as well as different avenues of experimentation based on the insights they have gained.

Pilpel and his team believe that genetic conditioned response may be a widespread means of evolutionary adaptation that enhances survival in many organisms – one that may also take place in the cells of higher organisms, including humans. These findings could have practical implications, as well. Genetically engineered microorganisms for fermenting plant materials to produce biofuels, for example, might work more efficiently if they gained the genetic ability to prepare themselves for the next step in the process.

Prof. Yitzhak Pilpel’s research is supported by the Ben May Charitable Trust and Madame Huguette Nazez, Paris, France.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

Jennifer Manning | Newswise Science News
Further information:
http://www.acwis.org

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>