Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Social mobility: Study shows bacteria seek each other out

30.07.2003


A study by Princeton University scientists has shown that bacteria actively move around their environments to form social organizations. The researchers placed bacteria in minute mazes and found that they sought each other out using chemical signals.



Biologists have become increasingly aware of social interactions among bacteria, but previously believed that clusters formed only when bacteria randomly landed somewhere, then multiplied into dense populations. The discovery that they actively move into gatherings underscores the importance of bacterial interactions and could eventually lead to new drugs that disrupt the congregating behavior of harmful germs, said Jeffry Stock, a professor of molecular biology and co-author of the paper.

"It makes sense, but it’s surprising that it’s as pervasive as it now seems to be," said Stock.


The researchers observed the gathering behavior in E. coli as well as in V. harveyi, a marine bacteria that glows when it achieves a high-density population. They found that when placed in mazes the bacteria congregated in small rooms and dead-end pathways. Once clustered, the V. harveyi turned on the genes that make them glow.

Biologists had previously believed that bacteria’s ability to move and follow chemical signals - a process called chemotaxis - was primarily a means of dispersing and seeking food. The new study shows that chemotaxis may also be important for facilitating cooperative behavior.

The work was a collaboration between Stock’s lab in biology and that of Robert Austin, a professor of physics. Emil Yuzbashyan, a graduate student in Austin’s noticed unusual clumping when he put E. coli into microscopically small mazes made of silicone. Biologists in Stock’s lab supplied mutant strains of bacteria that lacked genes necessary for sensing chemical signals and chemotaxis. They found that bacteria themselves emit a key chemical attractant and that those lacking the gene for the receptor that senses that attractant did not cluster as normal bacteria did.

Disrupting chemotaxis could be a route to attacking biofilms, a common type of bacterial interaction in which they form a colony that is resistant to antibiotic drugs and chemicals, the researchers said. Biofilms pose a common danger to patients receiving medical implants and cause trouble for ships that develop biofilms on their hulls.

Clustering also allows bacteria to perform a coordinated activity called quorum sensing in which they turn on certain genes only when they sense that they are part of a dense population. Some disease-causing bacteria are believed to rely on quorum sensing in mounting a successful infection. The V. harveyi in the experiment glowed as a result of quorum sensing after they gathered into a dense population.

"Our paper points out that you don’t necessarily need growth to achieve quorum sensing," said Peter Wolanin, a postdoctoral researcher in Stock’s lab. "The bacteria can actively seek each other out to engage in collective social behavior."

The behavior observed in the experiment also may have been a survival mechanism, said Sungsu Park, a postdoctoral researcher in Austin’s lab and first author of the paper. The research was conducted with the bacteria in a nutrient-depleted environment that resembles the natural conditions for bacteria much of the time. "The bacteria are chasing amino acids released from their own cell bodies during starvation conditions," said Park. "So by getting close to each other they have a better chance of getting nutrients."

The researchers also have developed a mathematical model that simulates the bacterial congregation, said Park. They plan further research to investigate the relation between bacterial behavior and the size and geometry of their physical environment.

| Princeton University
Further information:
http://www.princeton.edu

More articles from Life Sciences:

nachricht Antimicrobial substances identified in Komodo dragon blood
23.02.2017 | American Chemical Society

nachricht New Mechanisms of Gene Inactivation may prevent Aging and Cancer
23.02.2017 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>