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 The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke 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: 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

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>