Fluctuating environments can help cooperating bacteria

October 12, 2017
bacteria

Cooperating bacterial populations are more likely to survive in changing habitats, new research shows.

Dr Mauro Mobilia, from the University of Leeds, and Professor Erwin Frey and Karl Wienand, from Ludwig-Maximilians-University in Munich, have mathematically modelled competing in an environment with randomly fluctuating amounts of resources.

Their findings, published in Physical Review Letters, showed that a randomly changing environment can create a level playing field between self-serving and bacteria that work together.

Like other biological communities, bacterial collectives engage in social interactions that promote their survival. For example cooperating bacteria that produce and secrete compounds which stimulate colony growth are found in many despite the fact this uses a large amount of their energy.

In a stable environment, a bacterial strain that makes this energy sacrifice often dies out because it cannot reproduce at the same rate as bacteria that is "freeloading". Using mathematical models, the researchers were able to simulate environments where various community sizes of cooperative and freeloading bacteria had to compete for randomly switching levels of resources.

The study showed that a random switch from resource abundance to scarcity reduces the size of a bacterial community, giving the cooperating bacteria a fighting chance against their freeloading rivals.

Study co-author Dr Mobilia, from the School of Mathematics at Leeds, said: "Generally, the environments where you find bacteria are constantly changing. Our bodies, for example, with their ever-shifting levels of hormones and nutrients, provide a highly variable environment to a number of microorganisms.

"The study showed that a random switch from resource abundance to scarcity reduces the size of a , giving the cooperating bacteria a fighting chance against their freeloading rivals."

First author Karl Wienand, a biophysicist from LMU Munich, said: "Some of the cooperative behaviour of bacteria can appear at odds with the well-known idea of 'survival of the fittest.' Bacteria don't have brains or social conventions to enforce cooperation, but in analysing the combined effects of environment and population on the survival of a , our models show that a variable environment allows bacteria to overcome the price of cooperation."

Bacteria are generally considered unsophisticated organisms, but there is evidence that shows microbial communities are complex systems, with bacteria having intricate relations with their environment and among themselves.

Dr Mobilia said: "More modelling work is needed but our approach can be used to study different types of bacterial interactions and cooperation to further unravel the social lives of bacteria.

"A better understanding of the way bacteria interacts with its could even have an impact on how best to cultivate and how to treat bacterial infections."

Explore further: Bacteria avoid age defects through collective behaviour

More information: Karl Wienand et al. Evolution of a Fluctuating Population in a Randomly Switching Environment, Physical Review Letters (2017). DOI: 10.1103/PhysRevLett.119.158301

Related Stories

Bacteria avoid age defects through collective behaviour

July 14, 2016

As they age, more and more defects arise in most organisms. Researchers from the Niels Bohr Institute have discovered that microorganisms like bacteria can keep a colony young by practicing a common strategy for propagation. ...

Bacteria change a liquid's properties and escape entrapment

June 28, 2017

A flexible tail allows swimming bacteria to thin the surrounding liquid and to free themselves when trapped along walls or obstacles. This finding could influence how bacterial growth on medical, industrial, and agricultural ...

Cooperating bacteria isolate cheaters

December 8, 2015

Bacteria, which reciprocally exchange amino acids, stabilize their partnership on two-dimensional surfaces and limit the access of non-cooperating bacteria to the exchanged nutrients.

Dependency can be an evolutionary advantage

November 7, 2016

It has been known for quite some time that genetically modified bacteria, which have lost their ability to produce certain amino acids and retrieve these nutrients from their environment grow better than bacteria, which produce ...

Bacteria are individualists

May 10, 2016

No two bacteria are identical – even when they are genetically the same. A new study from researchers from Eawag, ETH Zurich, EPFL Lausanne, and the Max Planck Institute for Marine Microbiology in Bremen reveals the conditions ...

Good bacteria vital to coral reef survival

June 23, 2016

Scientists say good bacteria could be the key to keeping coral healthy, able to withstand the impacts of global warming and to secure the long-term survival of reefs worldwide.

Recommended for you

Spider-web 'labyrinths' may help reduce noise pollution

October 17, 2017

(Phys.org)—Researchers have demonstrated that the geometry of a natural spider web can be used to design new structures that address one of the biggest challenges in sound control: reducing low-frequency noise, which is ...

A miniature laser-like device for surface plasmons

October 17, 2017

Researchers at ETH Zurich have developed a miniature device capable of producing laser-like beams of a particular kind of electromagnetic wave called a surface plasmon. Surface plasmons can be focused much more tightly than ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.