Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers develop technique for bacteria crowd control

19.04.2007
A surprising technique to concentrate, manipulate and separate a wide class of swimming bacteria has been identified through a collaboration between researchers at the U.S. Department of Energy's Argonne National Laboratory, Illinois Institute of technology, University of Arizona at Tucson and Cambridge University, U.K. This device could have enormous applications in biotechnology and biomedical engineering, including use in miniaturized medical diagnostic kits and bioanalysis.

The technique is based on the transmission of tiny electric current in a very thin film sample cell containing a colony of bacteria. The current produces electrolysis that changes the local pH level in the vicinity of the electrodes. The bacteria, uncomfortable with the changes in pH, swim away from the electrodes and ultimately congregate in the middle of the experimental cell. Concentrated bacteria form self-organized swirls and jets resembling vortices in vigorously stirred fluid.

The method, which is suitable for flagellated bacteria such as E. coli, Bacillus subtilis, among many others, relies on the ability of bacteria to swim toward areas of optimal pH level. The bacteria live in an environment of a specific pH level, so that an increase or decrease of pH stimulates the bacteria to avoid areas of non-comfortable pH and swim in the direction of pH gradient. The researchers used an electric current to create a controlled deviation of the pH levels from the bulk values. Since only living bacteria respond to the pH stimulation, using this method can separate living and dead cells or bacteria with different motility.

The device, capable to change the thickness of a film from 1mm to 1 micron (with accuracy of 5 percent) and control the position of electrodes, is intended to separate and concentrate small quantities of living and dead microorganisms in confined spaces. It can be used for the purposes of express bioanalysis, diagnostic and identification of small bacterial samples, and separation sicken/live cells. A patent for the device is currently pending.

... more about:
»Argonne »Living »pH level

“Using this method, our research succeeded in dramatically increasing the concentration of microorganisms in tiny fluid drops and films. Unlike traditional centrifuging techniques, the new approach allows selective concentration of healthy cells,” said Andrey Sokolov, Ph.D. student from Illinois Institute of Technology and contributor to the research.

In addition to the development of the device used in the experimentation, research findings uncovered the explanation for the long-standing fundamental questions on the properties of collective and organized motion in the systems of interacting self-moving objects. Besides swimming bacteria, other examples include bird flocks, fish schools, motor proteins in living cell, and even swarms of communicating nano-robots.

“We have presented experimental studies of collective bacterial swimming in thin fluid films where the dynamics are essentially two-dimensional and the concentration can be adjusted continuously,” explained Igor Aronson, physicists at Materials Science Division, Argonne National Laboratory. “Our results provide strong evidence for the pure hydrodynamic origin of collective swimming, rather than chemotactic mechanisms of pattern formation when microorganisms just follow gradients of a certain chemical, such as nutrient, oxygen, or other.”

Detailed results of these findings have been published in Physical Review E and in Physical Review Letters.

Funding for this research was provided by the U.S. Department of Energy's Office of Basic Energy Science.

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 managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

For more information, please contact Sylvia Carson (630/252-5510 or scarson@anl.gov) at Argonne.

Sylvia Carson | alfa
Further information:
http://www.anl.gov

Further reports about: Argonne Living pH level

More articles from Life Sciences:

nachricht Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

nachricht First transcription atlas of all wheat genes expands prospects for research and cultivation
17.08.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>