Navigation Links
Research Throws Light on Adaptation of E.coli to Changing Conditions

Forthcoming in Physiological and Biochemical Zoology, a fascinating new selection of papers collects leading experimental research in evolution and artificial selection, providing insight into how organisms adapt to changing environmental conditions and fluctuations.

Dr. James Hicks, Editor in Chief of PBZ, explains the momentum behind this collection of papers: "This exciting approach experimental evolution allows scientists to investigate the fundamental mechanisms of evolution. Prior to the advent of contemporary laboratory techniques, inferences about evolution were based on observation. Now, we can study evolutionary change as it is happening, by selecting organisms that change rapidly, such as the fruit fly or E. coli. This advantage allows scientists to investigate how changes occur and how they affect an organism's individual physiology and overall community."

In the July/August 2007 issue, the first of three issues that will contain articles from the collection, Bradley S. Hughes, Alistair J. Cullum, and Albert F. Bennett (University of California, Irvine) explore the effect on E. coli of fluctuating acidity, an especially important environmental factor for the bacteria.

E. coli may spend hundreds or thousands of generations in the relatively neutral-acidity colon, with brief exposure to the extreme acidity of the stomach and modest alkalinity in the small intestine during colonization of a new host. With modern sewage handling (or mishandling), the bacteria may also experience exposure to the ocean, with a pH near 8.0, before infecting a new host.

To assess how E. coli might adapt to different environmental conditions, the researchers observed four groups of bacteria. One group was exposed to constant acidity (pH of 5.3) and another to constant alkalinity (pH of 7.8). A third group was exposed to randomly fluctuating pH levels, and the fourth was exposed to pH levels that cycled daily between acidi c and basic conditions.

After at least 1,000 generations, the researchers exposed the groups to either an acidic or basic environment. The groups exposed to acid or base for the entire period had developed into specialists that is, they displayed significant fitness gains when transitioning into their preferred environment.

In contrast, the groups that evolved in variable pH environments exhibited generalist fitness patterns, with neither group having any significant fitness loss in any of the environments. Interestingly, the researchers also found that there was no significant cost to being a generalist at any tested pH level: "Overall, these comparisons suggest that the jack-of-all-trades may be a master of at least some as well," the researchers write.

"What is interesting here is that the complex patterns of adaptation in the various pH regimes were so different among the groups and revealed the first empirical characterization of the intricacies of evolution in response to variable pH," explain the authors. "Plans for future studies include the extension of this experimental evolution system applied to . . . ways in which E. coli may be evolving fitness to survive within the coastal ecosystem or the human host."


'"/>




Related medicine news :

1. Kidney Stones - Interesting New Research implicates bacteria as its cause
2. Researchers urge caution in using ear tube surgery
3. Paracetamol May Cause Live Damage Warns Consumer Education and Research Centre
4. Researchers Scale to assess the Severity of Epilepsy in Kids
5. Research of Ritalin
6. Researchers trick Alzheimers Enzyme
7. Researchers find new HIV hiding place
8. A Compilation of recent Diabetes Research articles
9. Research on causes for falling helps develop preventive strategies
10. New standards for Human Research Safety
11. Research on Celiac Disease in children
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:7/28/2017)... ... July 28, 2017 , ... ... of its budget on nutrition assistance programs. , Right now the most public ... . However, changes to other programs are under consideration, including WIC (Women, Infants, ...
(Date:7/28/2017)... ... July 28, 2017 , ... Kevin Harrington, one of the original Sharks from hit reality ... of a new DRTV campaign with My Real Earth. , Most people put their healthcare ... just as important as what we put in our bodies. After all, the skin is ...
(Date:7/28/2017)... OR (PRWEB) , ... July 28, 2017 , ... Date ... http://www.GlobalDragonTV.com , Like millions of first generation immigrants before her, Rose Hong ... beneficiary of generosity and sacrifice on the part of loving parents who made sure ...
(Date:7/28/2017)... ... 2017 , ... The DuPage County law firm of Mirabella Kincaid Frederick ... Ms. Cusack joins the team ready to provide clients with vigorous representation in ... in Peoria, Illinois, with a BA in Social Work. She earned her JD from ...
(Date:7/28/2017)... ... July 28, 2017 , ... As many parents, students, and teachers are getting ... sharpen mental acuity and address mental fatigue that can accompany long study hours, homework ... that can not only helps with school work but also in day-to-day functions on ...
Breaking Medicine News(10 mins):
(Date:7/28/2017)... CHICAGO, July 28, 2017 Hill-Rom Holdings, Inc. ... fiscal third quarter ended June 30, 2017, and updated ... For the fiscal third quarter, ... to $0.68 per diluted share in the prior-year period. ... of $0.39 per diluted share primarily related to the ...
(Date:7/28/2017)... , July 28, 2017 EnvoyHealth, a Diplomat company, ... a program for CleverCap LITE, a technology designed to ... to deliver innovative health technology solutions and services that ... CleverCap LITE offers medication monitoring ... bottle cover: Records ...
(Date:7/27/2017)... -- Zimmer Biomet Holdings, Inc. (NYSE and SIX: ZBH) today reported ... The Company reported second quarter net sales of $1.954 ... period, and an increase of 2.1% on a constant ... from the LDR Holding Corporation acquisition, second quarter 2017 ... or 0.3% on a constant currency basis. ...
Breaking Medicine Technology: