Mechanical forces control the architecture of bacterial biofilms

October 30, 2015, University of Cologne

As hide-outs for bacteria, biofilms cause problems for antibiotic treatment or the cleaning of medical tubes. They contribute to the spreading of antibiotic-resistant bacterial strains. A biofilm is created when bacteria attach to surfaces and multiply. Gradually, bacterial subpopulations can develop different properties although they originated from the same cell. However, very little is known about how this heterogeneity contributes to the development of structure in such biofilms.

At the University of Cologne, biophysicists in the lab of Professor Berenike Maier were now able to show how differential can lead to cell sorting in , thereby determining their architecture. In their publication in the journal eLife, the team headed by the biophysicist Enno Oldewurtel showed how specific mechanical forces can be the key to the structure of a biofilm. Bacteria with different surface structures organized themselves in a "tug of war": the cells actively moved in the direction in which they could pull the strongest onto neighboring bacteria.

The bacterium Neisseria gonorrhoeae controls mechanical interactions among cells with extensions called pili. These rod-shaped structures function like grappling hooks between cells: the pili of different cells get caught and then shortened. This creates mechanical forces between cells. By means of targeted genetic modifications, the research team succeeded in steering the degree of entanglement between pili and hence the interaction forces between cells. These forces were measured using nanotechnology. In a mix of bacteria that interact with each other to different degrees, the cells sorted themselves according to the mechanical forces they exerted among one another.

All in all, the research showed that different mechanical interactions among can determine the architecture of biofilms. Similar mechanisms have already been identified in the positioning of cells in embryonic development. Hence the research has uncovered a fundamental similarity in the development processes of biofilms and embryos: differential physical interactions between the are important for their sorting. In the future, the question will be in how far this cell sorting strengthens the biofilm's resilience towards external stress.

Explore further: Biologists discover bacteria communicate like neurons in the brain

More information: Enno R Oldewurtel et al. Differential interaction forces govern bacterial sorting in early biofilms, eLife (2015). DOI: 10.7554/eLife.10811

Related Stories

Bacteria are wishing you a Merry Xmas

December 22, 2014

A bacterium has been used to wish people a Merry Xmas. Grown by Dr Munehiro Asally, an Assistant Professor at the University of Warwick, the letters used to spell MERRY XMAS are made of Bacillus subtilis, a non-pathogenic ...

Strategies to decrease bacterial colonization

September 14, 2015

Among the bacterial infections that are most difficult to treat, chronic infections associated with bacterial biofilms are one of the most hazardous. Bacterial biofilms are densely packed communities of microbial cells surrounded ...

Key to pathogenic slime uncovered

September 3, 2014

(Phys.org) —Dental plaque, the sludge in hot springs and black slime inside of toilets are all examples of biofilms, made of slick communities of bacteria that also play roles in many diseases.

Recommended for you

When does one of the central ideas in economics work?

February 20, 2019

The concept of equilibrium is one of the most central ideas in economics. It is one of the core assumptions in the vast majority of economic models, including models used by policymakers on issues ranging from monetary policy ...

Research reveals why the zebra got its stripes

February 20, 2019

Why do zebras have stripes? A study published in PLOS ONE today takes us another step closer to answering this puzzling question and to understanding how stripes actually work.

Physicists 'flash-freeze' crystal of 150 ions

February 20, 2019

Physicists at the National Institute of Standards and Technology (NIST) have "flash-frozen" a flat crystal of 150 beryllium ions (electrically charged atoms), opening new possibilities for simulating magnetism at the quantum ...

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.