Featured Research

from universities, journals, and other organizations

Bacteria Take The Path Of Least Resistance

Date:
July 7, 2005
Source:
National Science Foundation
Summary:
Researchers have reported new information about how certain bacteria propel themselves from one place to another. Insight into bacterial micro-movement will benefit scientists and engineers developing nano-scale mechanical devices that may one day push fluids and transport molecules without the aid of pumps or electrical charges.

Escherichia coli cells use long, thin structures called flagella to propel themselves. These flagella form bundles that rotate counter-clockwise, creating a torque that causes the bacterium to rotate clockwise.
Credit: Nicolle Rager Fuller, National Science Foundation

Researchers have reported new information about how certain bacteria propel themselves from one place to another. Insight into bacterial micro-movement will benefit scientists and engineers developing nano-scale mechanical devices that may one day push fluids and transport molecules without the aid of pumps or electrical charges.

Related Articles


The findings, published in the June 30 issue of the journal, Nature, may also help elucidate how pathogens traverse the human body when causing disease.

Using a novel system of microscopic channels, Harvard University researchers separated individual Escherichia coli cells from their typical "swarm" and videotaped them as they swam over different types of surfaces. A laboratory workhorse and common gastrointestinal bacterium, E. coli, preferred to swim near a gel-like porous surface with characteristics similar to biological tissues rather than near a glassy, solid one. In fact, they swam next to the porous surface for much longer periods of time.

First author Willow DiLuzio said, "Now that we've established the bacterium's preference to swim toward a specific kind of surface, we hope to harness this basic information and focus on how to use it to direct movement in microfluidic, cell-based bioassays and sensors."

The team developed a new technique to fabricate microchannels only 10 microns wide, or one-tenth the width of an average human hair. The walls of the channels were either a porous agar or a solid, commercially available silicone-rubber compound.

E. coli use long, whip-like structures called flagella to propel themselves. Motors in the cell's wall spin the flagella into bundles that rotate counter-clockwise, creating a twist that causes the bacterium to rotate clockwise, or towards the right when viewed from above.

If cells were introduced to each end of the channel containing agar on the bottom, the cells preferentially swam on the right-hand side of the microchannel resulting in an ordered movement that resembled cars driving on a two-way street. And the microbes swimming closer to the agar surface moved faster than those swimming near the solid surface.

The authors propose that the bacteria closer to the porous surface experience less resistance and thus move faster.

"Because of E. coli's size, relative to the spacing of surrounding water molecules, it's analogous to a human trying to move through thick honey," said DiLuzio. "Now, an entirely new set of hydrodynamic properties have to be considered in order to understand their movement as well as replicate it in man-made nano-devices."

The surfaces of cells in the human body are often coated with a layer similar to agar. Future research into microbial movement will also be helpful in understanding how human infectious diseases develop and how infection might be halted in the body.

DiLuzio is supported by the National Science Foundation's Education Human Resources directorate through an award made to Harvard's Integrated Training Program in Biomechanics.


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

National Science Foundation. "Bacteria Take The Path Of Least Resistance." ScienceDaily. ScienceDaily, 7 July 2005. <www.sciencedaily.com/releases/2005/07/050707062959.htm>.
National Science Foundation. (2005, July 7). Bacteria Take The Path Of Least Resistance. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2005/07/050707062959.htm
National Science Foundation. "Bacteria Take The Path Of Least Resistance." ScienceDaily. www.sciencedaily.com/releases/2005/07/050707062959.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins