Nav: Home

NUS-led research team discovers how bacteria sense salt stress

July 09, 2012

A team of scientists led by Assistant Professor Ganesh S Anand and Professor Linda J. Kenney from the National University of Singapore (NUS) Department of Biological Sciences (DBS) and the Mechanobiology Institute (MBI) has discovered how bacteria respond to salts in their environment and the ways in which salts can alter the behaviour of specialised salt sensor bacterial proteins.

This novel finding sheds light on how microbes detect levels of salts or sugars in their watery environments - a problem in biology that has been studied for more than 30 years.

The NUS scientists found that microbes do this by specialised molecules or proteins on the bacterial surface that change shape in response to changes in salt concentration. This is relevant not only to bacteria, but also cells from all organisms which detect and respond to changes in environmental salts and sugars.

The scientists from NUS and the University of Illinois-Chicago (UIC) first published their findings in the EMBO Journal on 30 May 2012.

Salt detecting proteins are like springs

Bacteria have elaborate mechanisms for sensing and responding to changes in the environment. One of the important environmental stresses for bacteria is the changing concentration of salts. For instance, some can live in fresh water (a low salt environment) or in the guts of humans (high salt environment).

Using a powerful combination of a tool called amide hydrogen/deuterium exchange mass spectrometry (HDXMS), accompanied by molecular biology and biochemistry, the scientists from NUS probed how changes in salt concentrations are sensed by a receptor protein.

They found that salt detecting proteins are like molecular springs, or "slinky toys". The proteins are constantly shifting from a condensed spring form to an extended form. Increasing the salt concentration dampens this spring-like movement, which activates the protein. In other words, the less spring-like the protein, the higher is its activity. This protein movement may provide a unified model of how bacteria sense their environment.

Application of the phenomenon

This study is an example of basic science with immediate applications. Recognising that diverse proteins operate as molecular springs whose spring-like movement can be dampened is fundamental to understanding how these proteins work. This study also underscores the role of water in biology. It demonstrates how salts and sugars can alter biological properties of proteins through the effects on water and is relevant for understanding life processes across species from bacteria to humans.

Further research

The NUS research team is now working on studying the protein in its native membrane by embedding the bacterial sensor protein in an artificial membrane. They hope to understand how the membrane contributes to overall protein activity, structure, stability and responses to salts.

-end-



National University of Singapore
Conducting shell for bacteria
Under anaerobic conditions, certain bacteria can produce electricity. This behavior can be exploited in microbial fuel cells, with a special focus on wastewater treatment schemes.
Controlling bacteria's necessary evil
Until now, scientists have only had a murky understanding of how these relationships arise.
Bacteria take a deadly risk to survive
Bacteria need mutations -- changes in their DNA code -- to survive under difficult circumstances.
How bacteria hunt other bacteria
A bacterial species that hunts other bacteria has attracted interest as a potential antibiotic, but exactly how this predator tracks down its prey has not been clear.
Chlamydia: How bacteria take over control
To survive in human cells, chlamydiae have a lot of tricks in store.
Stress may protect -- at least in bacteria
Antibiotics harm bacteria and stress them. Trimethoprim, an antibiotic, inhibits the growth of the bacterium Escherichia coli and induces a stress response.
'Pulling' bacteria out of blood
Magnets instead of antibiotics could provide a possible new treatment method for blood infection.
New findings detail how beneficial bacteria in the nose suppress pathogenic bacteria
Staphylococcus aureus is a common colonizer of the human body.
Understanding your bacteria
New insight into bacterial cell division could lead to advancements in the fight against harmful bacteria.
Bacteria are individualists
Cells respond differently to lack of nutrients.

Best Science Podcasts 2017

We have hand picked the best science podcasts for 2017. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.

Now Playing: Radiolab

Truth Trolls
Today, a third story of folks relentlessly searching for the truth. But this time, the truth seekers are an unlikely bunch... internet trolls.


Now Playing: TED Radio Hour

Rethinking School
For most of modern history, humans have placed smaller humans in institutions called schools. But what parts of this model still work? And what must change? This hour, TED speakers rethink education.TED speakers include teacher Tyler DeWitt, social entrepreneur Sal Khan, international education expert Andreas Schleicher, and educator Linda Cliatt-Wayman.