Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Quickly evolving bacteria could improve digestive health

19.05.2010
When the forces of evolution took over an experimental strain of bacteria, it derailed an experiment Duke and NC State researchers thought they were conducting, but led to something much more profound instead.

The researchers used a colony of mice raised in a large plastic bubble, called an isolator, that was completely sterile, lacking even a single bacterium. They introduced a single type of bacteria into the mouse colony, but it mutated quickly into different types, making new bacteria that were hardier inside of the mice than the original bacterium was.

"In some regards, this is one of the best demonstrations of evolution ever carried out in a laboratory," said William Parker, Ph.D., assistant professor in the Duke Department of Surgery. "This is the first time the evolution of bacteria has been monitored for a period of years in an incredibly complex environment."

Parker said the work illustrates the power of evolution in creating diversity and in filling ecological niches. "This study also strengthens the idea that we could harness evolution in the laboratory to develop microbes for use in biotechnology and in medicine," Parker said.

The results, which appear in the journal Applied and Environmental Microbiology, indicate that "experimental evolution," or evolution controlled in a laboratory setting, could be used to develop new strains of bacteria for use as probiotic substances, which are living organisms used for intestinal and digestive therapies.

The scientists put a single strain of bacteria, brushed onto the mice, in a colony of otherwise bacteria-free mice. The study bacteria were engineered to make a structure (called a type 1 pilus) that helps them stick to things. The researchers hoped to learn how the molecule would affect the interaction between the bacteria and the mice.

"We were surprised, because we thought we would be able to study this engineered bacterium for a while, but we were wrong," Parker said. The bacteria started to mutate and quickly lost the pilus structure that had been engineered into them. The single homogeneous strain was rapidly evolving into a diverse community of organisms.

"We did a variety of experiments to rule out contamination as the source of the diversity," Parker said. "It became clear that evolution was messing up our experiment. At that point, because the evolutionary process seemed to be driving the bacteria to live more effectively in the mouse gut, and because developing bacteria to live more effectively in the gut is one of our primary goals, we decided to let the process run and see where it would go."

Over the three-year study period, the bacterial population remained diverse and appeared to adapt significantly well to the environment in the digestive tracts of the mice. "The bacteria colonized better in the mice by the end of the experiment than at the beginning," Parker said, with more than a three-fold increase in the density of bacteria within the gut by the end of the experiment.

"We see a number of evolutionary adaptations occurring in the bacteria, including a potential increase in resistance to cell death," Parker said. One future goal of the research is to understand the genetic changes responsible for the adaptations.

A large team composed of scientists from Duke and from North Carolina State University was involved in the study, which took place over the course of about seven years, including preparation prior to the three years in the isolator and the analyses of the bacteria afterwards. The team included Sean M. Lee, Aaron Wyse, Aaron Lesher, Mary Lou Everett, Linda Lou, Zoie E. Holzknecht, John F. Whitesides, Dawn E. Bowles, Shu S. Lin, and R. Randal Bollinger from Duke, and Susan L. Tonkonogy, Paul E. Orndorff, Patricia A. Spears, and Donna Kronstadt from North Carolina State.

The work was funded by the National Institutes of Health through the Center for Gastrointestinal Biology and Disease and the Duke Human Vaccine Institute Flow Cytometry Core Facility.

Mary Jane Gore | EurekAlert!
Further information:
http://www.duke.edu

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>