Featured Research

from universities, journals, and other organizations

Bacteria's Survival Ration: Ability To Feed On Waste DNA Can Mean Difference Between Life And Death

Date:
May 25, 2006
Source:
University of Southern California
Summary:
The ubiquitous bacteria E. coli rank among nature's most successful species for lots of reasons, to which biologists at the University of Southern California have added another: in a pinch, E. coli can feast on the DNA of their dead competitors. A research team led by Steven Finkel, assistant professor of molecular and computational biology in the USC College of Letters, Arts and Sciences, had already shown that DNA is an acceptable source of nutrients for bacteria.

The ubiquitous bacteria E. coli rank among nature's most successful species for lots of reasons, to which biologists at the University of Southern California have added another: in a pinch, E. coli can feast on the DNA of their dead competitors.

A research team led by Steven Finkel, assistant professor of molecular and computational biology in the USC College of Letters, Arts and Sciences, had already shown that DNA is an acceptable source of nutrients for bacteria.

The team's latest study, presented in the June 1 issue of the Journal of Bacteriology, finds that DNA is a critical food source in the battle of the fittest. Bacteria that stay alive just a little longer than their counterparts get a double reward: the competition for food lessens, and the supply of nutrients increases.

"The bacteria actually eat the DNA, and not only that, they can use the DNA as their sole source of nutrition," Finkel said.

In hindsight, it should come as no surprise that DNA can serve as a meal for microbes.

"You're surrounded by living things, and living things die," Finkel said. "Where does all that stuff go? Why aren't we up to our ears in DNA, in ribosomes, in plant protein?

"A lot of decay is microbial, and nobody ever thinks about it."

Finkel calls this phenomenon "nutritional competence" to distinguish it from natural competence, defined as the ability of cells to assimilate waste DNA in order to mutate or repair their genomes.

Natural competence is potentially risky, Finkel said, since bad mutations can result, "but there should be no genetic cost to eating [the DNA]."

The study identified eight genes in E. coli that are necessary for nutritional competence. Without any one of these genes, the bacteria cannot consume DNA and lose their competitive advantage.

"The gene family is found in many other species," the authors reported, "suggesting that the use of DNA as a nutrient may be a widespread phenomenon."

The concept of nutritional competence could have applications to medical research, as the DNA from dead cells in the human body may be sustaining harmful bacteria.

One of the pathogens implicated in cystic fibrosis is suspected of feeding on DNA in lung tissue, Finkel said. Biofilms, which have been linked to chronic infections, also may harbor nutritionally competent germs.

If researchers succeeded in turning off nutritional competence in such pathogens, as Finkel did in E. coli, the advance might lay the groundwork for a new class of genetic antibiotics.

The study did not prove that all DNA decay is microbial. But Finkel discounted the significance of inorganic processes, citing the chemical stability of genetic material. If a thick layer of DNA were exposed to the sun, he said, only molecules at the top would break down chemically, while bacteria would eat the rest from the bottom up.

Nevertheless, Finkel said, DNA remains a backup nutrient for bacteria, being harder to digest than glucose and other simpler food sources.

The study's co-author was Vyacheslav Palchevskiy, a graduate student in molecular and computational biology. Funding came from the National Science Foundation and the National Institute of Aging.

Finkel's first study of nutritional competence, co-authored with Roberto Kolter of Harvard Medical School and published in 2001 in the Journal of Bacteriology, was an Editors' Choice of Science magazine.


Story Source:

The above story is based on materials provided by University of Southern California. Note: Materials may be edited for content and length.


Cite This Page:

University of Southern California. "Bacteria's Survival Ration: Ability To Feed On Waste DNA Can Mean Difference Between Life And Death." ScienceDaily. ScienceDaily, 25 May 2006. <www.sciencedaily.com/releases/2006/05/060525192640.htm>.
University of Southern California. (2006, May 25). Bacteria's Survival Ration: Ability To Feed On Waste DNA Can Mean Difference Between Life And Death. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2006/05/060525192640.htm
University of Southern California. "Bacteria's Survival Ration: Ability To Feed On Waste DNA Can Mean Difference Between Life And Death." ScienceDaily. www.sciencedaily.com/releases/2006/05/060525192640.htm (accessed September 16, 2014).

Share This



More Plants & Animals News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. 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:
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