Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

DNA: Bacteria’s survival ration

29.05.2006
Ability to feed on waste DNA can mean difference between life and death

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.

Carl Marziali | EurekAlert!
Further information:
http://www.usc.edu

More articles from Life Sciences:

nachricht Toward a 'smart' patch that automatically delivers insulin when needed
18.01.2017 | American Chemical Society

nachricht 127 at one blow...
18.01.2017 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>