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:6/26/2016)... (PRWEB) , ... June 26, 2016 , ... PawPaws ... a new product that was developed to enhance the health of felines. The formula ... , The two main herbs in the PawPaws Cat Kidney Support Supplement ...
(Date:6/26/2016)... (PRWEB) , ... June 26, 2016 , ... ... fertility once they have been diagnosed with endometriosis. These women need a treatment ... also require a comprehensive approach that can help for preservation of fertility and ...
(Date:6/25/2016)... ... June 25, 2016 , ... Austin residents seeking Mohs ... College of Mohs Surgery and to Dr. Russell Peckham for medical and surgical dermatology. ... treatment for skin cancer. The selective fellowship in Mohs Micrographic Surgery completed by Dr. ...
(Date:6/25/2016)... ... June 25, 2016 , ... "With 30 hand-drawn hand ... project," said Christina Austin - CEO of Pixel Film Studios. , ProHand Cartoon’s ... within Final Cut Pro X . Simply select a ProHand generator and drag ...
(Date:6/25/2016)... , ... June 25, 2016 , ... As a lifelong ... Cum Laude and his M.D from the David Geffen School of Medicine at UCLA. ... to Los Angeles to complete his fellowship in hematology/oncology at the UCLA-Olive View-Cedars Sinai ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... 2016 Roche (SIX: RO, ROG; OTCQX: RHHBY) ... Elecsys BRAHMS PCT (procalcitonin) assay as a dedicated testing ... With this clearance, Roche is the first IVD company ... for sepsis risk assessment and management. PCT ... PCT levels in blood can aid clinicians in assessing ...
(Date:6/23/2016)... , , , WHEN: ... , , , , LOCATION: , , , Online, with ... , EXPERT PANELISTS:  , , , Frost & Sullivan,s Global Vice ... Senior Industry Analyst, Divyaa Ravishankar and Unmesh Lal, Program Manager , ... industry is witnessing an exceptional era. Several new demand spaces, such ...
(Date:6/23/2016)... -- The vast majority of dialysis patients currently receive ... usually 3 times a week, with treatment times averaging ... equipment preparation and wait time.  This regimen can be ... who are elderly and frail.  Many elderly dialysis patients ... for some duration of time. Residents in ...
Breaking Medicine Technology: