Featured Research

from universities, journals, and other organizations

Microbiology Team Probes Bacterium's Surprising Survival Tactics

Date:
April 19, 2002
Source:
National Science Foundation
Summary:
A team of microbiologists affiliated with the University of Massachusetts at Amherst (UMass) has uncovered the unusual survival strategies used by a common bacterium. The finding could have implications in cleaning up contaminants ranging from petroleum to uranium.

A team of microbiologists affiliated with the University of Massachusetts at Amherst (UMass) has uncovered the unusual survival strategies used by a common bacterium. The finding could have implications in cleaning up contaminants ranging from petroleum to uranium. Results of the National Science Foundation (NSF)-funded study by UMass microbiologist Derek Lovley and colleagues will be published in the April 18 issue of Nature. The research was also funded by the U.S. Department of Energy.

Scientists have long known that the bacteria species, Geobacter metallireducens, is commonly found in soil and consumes metals - specifically, iron and manganese oxides. The new findings detail the microorganisms' intriguing survival tactics. First, the species is apparently able to locate and home in on the metal that serves as its food source. "This is the first microorganism found to have a built-in sensor that allows it to essentially 'sniff out' metals," said Lovley. And if a source of iron or manganese is not nearby, the bacterium - which was previously believed to be incapable of movement - can essentially decide to grow flagella, the whip-like structures that enable bacteria to swim.

"This work demonstrates again that basic research, in addition to answering the questions for which it was specifically designed, can also produce totally unexpected insights into the natural world," says Susan Porter Ridley, program director in NSF's division of molecular and cellular biosciences. "In this case, the sequence of bases in a microbe's DNA led to the discovery that the microbe can actually sense and locate chemicals it needs. This knowledge, in turn, shows great promise for helping us solve the problem of environmental pollution."

Scientists were already aware that some bacteria species, such as the well-studied E coli, are able to sense and swim toward sugars. But scientists had never seen Geobacter swim, leading UMass researchers to wonder how it is that metals serve as its energy source.

Clues to the puzzles were found as Geobacter's genome was sequenced in collaboration with The Institute for Genomic Research in Rockville, Maryland. The Geobacter's genetic code revealed a startling discrepancy: "We looked at the complete genetic code, and saw clear evidence of genes for flagella, so we realized this bacterium does indeed have the genetic potential to swim," said Lovley. "The question then was, 'Does this have anything to do with Geobacter's growth on metals?'"

Lovley realized that in previous studies the ability of Geobacter to swim had always been analyzed when it had been grown on soluble metals, which are often used in laboratory experiments because they are easy to work with. No one had looked carefully at growth on the metal oxides that Geobacter actually uses in natural environments. When the researchers looked at cultures grown on iron oxide, the cells had produced flagella and were swimming.

The genome also contained genes which suggested that Geobacter might be able to sense chemicals in the environment. To see if this was also related to growth on metals, the scientists set up a series of microscope slides on which the bacteria needed to travel to reach the metal necessary for their survival. It turned out that the bacteria were growing flagella and swimming to the metal source. "These bacteria really do grow flagella in order to search for, and establish contact with, the soluble iron or manganese oxides they need," paper co-author Susan Childers said. Under the microscope, the microbes are cigar-shaped, and one to two microns long; 10,000 of them would measure an inch.

Once the bacterium reaches the metal, it is able to grow the short, hair-like structures called pili, which allow the bacterium to anchor itself to the metal source, ensuring growth.

The finding represents more than just an intriguing look at how microbes survive and thrive: these microbes can be used to clean up petroleum spills, and they may offer an efficient and economic solution to removing uranium from contaminated groundwater. Previous efforts at flushing uranium from the soil involved pumping water out of an area and removing the soil - a process which has proven to be both expensive and inefficient, Lovley said.

"Geobacters don't actually remove the uranium," explained Lovley, "but they do transform the metal from a soluble form to an insoluble form, so that it is no longer able to leach into the groundwater and eventually contaminate rivers."


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. "Microbiology Team Probes Bacterium's Surprising Survival Tactics." ScienceDaily. ScienceDaily, 19 April 2002. <www.sciencedaily.com/releases/2002/04/020418073221.htm>.
National Science Foundation. (2002, April 19). Microbiology Team Probes Bacterium's Surprising Survival Tactics. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2002/04/020418073221.htm
National Science Foundation. "Microbiology Team Probes Bacterium's Surprising Survival Tactics." ScienceDaily. www.sciencedaily.com/releases/2002/04/020418073221.htm (accessed July 30, 2014).

Share This




More Plants & Animals News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Raw: Otters Enjoy Water Slides at Japan Zoo

Raw: Otters Enjoy Water Slides at Japan Zoo

AP (July 30, 2014) River otters were hitting the water slides to beat the summer heatwave on Wednesday at Ichikawa City's Zoological and Botanical Garden. (July 30) Video provided by AP
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:
from the past week

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