Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A closer look yields new clues to why bacteria stick to things

26.03.2003


A bacterium’s ability to change its hairstyle may help in the effort to clean contaminated groundwater for drinking, according to Penn State researchers.



People are continually moving into places that are hot, sunny and arid where drinking water is in short supply, says R. Kramer Campen, Penn State graduate student in geosciences. "The imperative to find ways to clean groundwater is paramount," he told attendees today (March 25) at the 225th American Chemical Society national meeting in New Orleans.

In the ocean, bacteria can be released into the water to clean up oil spills, carried to the target by the same currents that transport the oil. Groundwater poses a more difficult problem as these single-cell organisms tend to adhere to certain minerals in the soil preventing them from following the pollutant’s trail. Bacterial adhesion is also responsible for many medical problems such as tooth decay and artificial limb and organ rejection. "There is a growing awareness that you need a molecular level understanding," says Campen. "At that level, the processes that cause a bacterium to adhere to a mineral in soil or to a tooth have to be the same."


For many years, scientists have noted that bacteria stick to iron particles in soil, but not to sand grains. Until recently, this has been explained by invoking the same forces that hold a balloon to the ceiling after you rub it on your sweater. Researchers thought that the tiny, negative electrical charges on sand grains repelled the negatively charged bacteria, while the positively charged iron attracted them.

However, Campen and his adviser, James Kubicki, assistant professor of geosciences, think it is all about the hair. Bacteria are covered with atomic-scale chains of complex sugar molecules with "one end fastened into the cell membrane and the rest extending outward," explains Campen. "The hair analogy is a good one."

The hairs, actually polymers, present a problem for the charge-based explanation because the strength of the attraction (or repulsion) depends on how close the objects are to each other. Because the charges are so small, at a distance of one hair-length no attraction should be felt.

Electrical charges may still be important, just not for the reasons previously thought. Polymers come in two varieties – one with no charge and another with positive and negative charges distributed along its length. A single bacterium has both, and the aggregate is known as a polymer brush.

Campen put polymers similar to those on bacteria, both charged and uncharged, into a liquid solution with iron and sand-like particles. He discovered that both adhered to the iron, challenging the idea that electrical forces are the cause of stickiness.

The charged hairs may have another purpose. "If you’re a bacterium in a nutrient-rich environment you’d like to stick around for while," says Campen. "If you’re in a nutrient-poor environment you’d rather decrease the chances that you’ll stick to surfaces."

To accomplish this, he thinks the bacterium may rearrange the positive and negative charges along its charged polymers in such a way that they would extend, allowing the whole brush to expand, contact surfaces, and become stuck. Or, in a different arrangement the charged hairs would scrunch up, flattening the brush and allowing the bacterium to be carried away.

Developing a method to control this behavior would provide scientists with the means to send bacteria where needed, or prevent them from accumulating where they can do harm.



The National Science Foundation provided funding for this project.

Andrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu/

More articles from Life Sciences:

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown 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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>