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 The Secret of the Rock Drawings
24.05.2019 | Max-Planck-Institut für Chemie

nachricht Chemical juggling with three particles
24.05.2019 | Rheinische Friedrich-Wilhelms-Universität Bonn

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New studies increase confidence in NASA's measure of Earth's temperature

A new assessment of NASA's record of global temperatures revealed that the agency's estimate of Earth's long-term temperature rise in recent decades is accurate to within less than a tenth of a degree Fahrenheit, providing confidence that past and future research is correctly capturing rising surface temperatures.

The most complete assessment ever of statistical uncertainty within the GISS Surface Temperature Analysis (GISTEMP) data product shows that the annual values...

Im Focus: The geometry of an electron determined for the first time

Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.

The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

On Mars, sands shift to a different drum

24.05.2019 | Physics and Astronomy

Piedmont Atlanta first in Georgia to offer new minimally invasive treatment for emphysema

24.05.2019 | Medical Engineering

Chemical juggling with three particles

24.05.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>