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 Molecular evolution: How the building blocks of life may form in space
26.04.2018 | American Institute of Physics

nachricht Multifunctional bacterial microswimmer able to deliver cargo and destroy itself
26.04.2018 | Max-Planck-Institut für Intelligente Systeme

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Why we need erasable MRI scans

New technology could allow an MRI contrast agent to 'blink off,' helping doctors diagnose disease

Magnetic resonance imaging, or MRI, is a widely used medical tool for taking pictures of the insides of our body. One way to make MRI scans easier to read is...

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

World's smallest optical implantable biodevice

26.04.2018 | Power and Electrical Engineering

Molecular evolution: How the building blocks of life may form in space

26.04.2018 | Life Sciences

First Li-Fi-product with technology from Fraunhofer HHI launched in Japan

26.04.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>