Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New method studies living bacteria cells

25.10.2004


Researchers at the U.S. Department of Energy’s Argonne National Laboratory have found a new way to study individual living bacteria cells and analyze their chemistry.



In research published today in Science, the scientists used high-energy X-ray fluorescence measurements for mapping and chemical analyses of single free-floating, or planktonic, and surface-adhered, or biofilm, cells of Pseudomonas fluorescens. The results showed differences between the planktonic and adhered cells in morphology, elemental composition and sensitivity to hexavalent chromium, a heavy-metal contaminant and a known carcinogen. The biofilm cells were more tolerant of the contaminant, while it damaged or killed the planktonic cells.

In addition to determining the chemical differences between the cells, the work also pioneers a potentially revolutionary new technique for investigating microbiological systems in natural subsurface environments. This study advanced the development of high-energy X-ray microprobes and methods for using the microprobes to investigate single bacterial cells. The new capabilities set the stage for future studies defining mineral-metal-microbe interactions in contaminated environments. “This technique also should be directly applicable to investigations of microbial processes in extreme subsurface environments and to studies of a variety of astrobiology topics, such as detection of past or present life in samples returned from Mars, or determinations of the origins of life,” said lead author Ken Kemner of Argonne’s Environmental Research Division.


No previously available techniques had the spatial resolution needed to analyze individual bacterial cells noninvasively and nondestructively. Recent developments at the Advanced Photon Source (APS) at Argonne enabled the production of X-ray beams small enough to probe single bacterial cells, which are typically one-hundredth the diameter of a human hair. The APS provides the nation’s most brilliant X-rays for research. In these experiments, scientists exposed both planktonic and biofilm cells to elevated concentrations of hexavalent chromium. The researchers then used X-ray fluorescence microscopy to measure the concentrations of elements in individual cells before and after exposure to the heavy metal. The results indicated that X-ray fluorescence analysis had distinguished living bacterial cells from dead cells for the first time. The analysis also showed that a bone-like mineral deposit had formed around the surface of the adhered cells. This deposit made the adhered cells much more tolerant than planktonic cells to elevated levels of the contaminant.

Next, the researchers used the energy tunability of the APS X-ray beamline for spectroscopy experiments on the bacterial systems. These experiments showed that the surface adherence of the biofilm cells promoted tolerance to the chromium and reduced its toxicity level. Finally, when the cells made the transition from the planktonic state to the biofilm state, the scientists observed changes in the concentrations of many transition metals required for bacterial life. These results suggest that X-ray fluorescence analysis might be useful for determining whether a bacterial cell is living or dead. “No other technique has been capable of determining the metabolic state of a single hydrated cell and the chemical speciation of metals on, in or near a bacterial cell,” Kemner said. “The achievements of this study have the potential to revolutionize the way scientists investigate mineral-metal-microbe systems.”

Other authors on the report, in addition to Kemner are Shelly D. Kelly, Edward J. O’Loughlin and Deirdre Sholto-Douglas (Environmental Research Division, Argonne); Barry Lai, Joerg Maser and Zhonghou Cai (Experimental Facilities Division, Argonne); Mark Schneegurt (Wichita State University); Charles F. Kulpa, Jr. (University of Notre Dame); and Kenneth H. Nealson (University of Southern California).

Funding for this project came from the Natural and Accelerated Bioremediation program of the U.S. Department of Energy’s Office of Biological and Environmental Research.

The nation’s first national laboratory, Argonne National Laboratory conducts basic and applied scientific research across a wide spectrum of disciplines, ranging from high-energy physics to climatology and biotechnology. Since 1990, Argonne has worked with more than 600 companies and numerous federal agencies and other organizations to help advance America’s scientific leadership and prepare the nation for the future. Argonne is operated by the University of Chicago for the U.S. Department of Energy’s Office of Science.

Donna Jones Pelkie | EurekAlert!
Further information:
http://www.anl.gov

More articles from Life Sciences:

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

nachricht Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>