Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers find mechanism bacteria use to target specific chemical contaminants

09.12.2003


New insight into the molecular-level interactions between bacteria and minerals may some day help scientists design bacteria with the express purpose of cleaning up toxic waste.



Hazardous waste experts know that certain bacteria can essentially eat toxic waste, reducing it to less noxious substances. But until now they didn’t know what mechanisms allowed these bacteria to devour chemicals.

A new study by Ohio State and Virginia Tech universities showed how a particular bacteria uses iron oxide, or rust, to breathe. The researchers found that key changes in the expression of genes in Shewanella oneidensis enable the microbe to recognize and bind specifically to iron oxides.


This finding could help researchers manipulate the bacteria to make it more effective in cleaning up petroleum products at toxic waste sites.

"In some situations, S. oneidensis is capable of using organic contaminants similar to oil as a source of energy,” said Steven Lower, a study co-author and an assistant professor of geological sciences at Ohio State. "Petroleum products are one of the main chemicals found in toxic waste dumps.

“Also, there’s little to no oxygen in these underground sites, so the bacteria have to adapt to anaerobic conditions,” said Lower, who is also a professor in the school of natural resources. This essentially means that in order for bacteria to grow and degrade an organic contaminate, it must be able to ‘breathe’ on something other than oxygen.”

The researchers hope to one day be able to tailor bacteria so it could target a specific contaminant.

Lower pointed out that one problem with using microbes to help clean up contaminated sites is getting the bacteria to the site and then ensuring that it remains in place.

Knowing which gene the bacteria express in an anaerobic environment may enable researchers to genetically manipulate the microbes so they prefer iron oxides only in the presence of oil and related waste products.

Lower conducted the work with Brian Lower and Michael Hochella, both with the department of geosciences at Virginia Tech. The results were presented December 8 at the fall meeting of the American Geophysical Union in San Francisco.

The researchers used a relatively new technique called biological force microscopy to measure the molecular forces between S. oneidensis and a crystal of iron oxide. Force microscopy lets scientists measure the minutest interactions between the surfaces of two substances. Such microscopes use an ultra-sensitive probe that can detect attractive and repulsive forces.

The researchers placed a small amount of S. oneidensis on the probe, which also acts as a cantilever, and a sample of iron oxide near the probe. A beam of laser light was then reflected off of the probe to determine if the bacteria-covered cantilever was bending toward or away from the iron oxide sample, and by how much.

“In principle it’s a very simple measurement that tells us whether or not a bacterium is attracted to an inorganic substance, and also gives us a precise measurement of that attraction," Lower said.

He and his colleagues also analyzed gene expression patterns in S. oneidensis to learn if different genes were expressed depending on what the bacteria uses to breathe.

Indeed, the researchers found that S. oneidensis produces two specific proteins under anaerobic conditions, which allow the microbes to bind to and breathe in, and therefore reduce, iron contained in the structure of a solid mineral.

“We’ve known for decades that this bacteria can use dissolved iron to breathe, but until now we really didn’t know how they could do this in nature, where most of the iron is embedded in the crystal structure of a solid mineral," Lower said. "This interaction is probably billions of years old, and may represent one of the first globally significant mechanisms for oxidizing organic matter to carbon dioxide."

This work was supported by grants from the U.S. Department of Energy and the National Science Foundation.


Contact: Steven Lower, (614) 292 1571; Lower.9@osu.edu
Written by Holly Wagner, (614) 292-8310; Wagner.235@osu.edu

Steven Lower | Ohio State University
Further information:
http://researchnews.osu.edu/archive/shewagu.htm

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

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

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | 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

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>