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 A new molecular player involved in T cell activation
07.12.2018 | Tokyo Institute of Technology

nachricht News About a Plant Hormone
07.12.2018 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

Im Focus: Substitute for rare earth metal oxides

New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals

Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.

Im Focus: A bit of a stretch... material that thickens as it's pulled

Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.

Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...

Im Focus: The force of the vacuum

Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.

The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

Expert Panel on the Future of HPC in Engineering

03.12.2018 | Event News

Inaugural "Virtual World Tour" scheduled for december

28.11.2018 | Event News

 
Latest News

A new molecular player involved in T cell activation

07.12.2018 | Life Sciences

High-temperature electronics? That's hot

07.12.2018 | Materials Sciences

Supercomputers without waste heat

07.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>