News from CEXS-UPF
Most living organisms are organized into populations consisting of a large number of individuals. This is so even in simple single-cell organisms such as bacteria that usually live in large communities called biofilms.
These communities can be in the order of millions of individuals and coexist in stress conditions due to the lack of nutrients and the presence of external toxic agents (such as antibiotics and chemical toxins). Despite having to cope with such complicated conditions, bacterial biofilms are notoriously resistant and difficult to eradicate.
On 22 July, Nature published a study jointly coordinated by researchers Jordi García-Ojalvo of the Department of Experimental and Health Sciences (CEXS) of UPF and Gurol Süel, of the University of California in San Diego (USA), which shows how the extraordinary resistance of biofilms is the result of resolving a social conflict between bacteria from inside and from the periphery of the bacterial community.
As García-Ojalvo explains, "in situations of restricted nutrients, bacteria in the peripheral area consume most of the available resources and thereby greatly limit the nutrients that reach the interior of the biofilm. Moreover, the interior depends on the periphery to protect itself from external attacks, in the same way as happened in walled cities in the past".
Jintao Liu, Arthur Prindle, Jacqueline Humphries, Marçal Gabalda-Sagarra, Munehiro Asally, Dong-yeon D. Lee, San Ly, Jordi Garcia-Ojalvo, Gürol M. Süel (2015), "Metabolic codependence gives rise to collective oscillations within biofilms", Nature,22 July, DOI: 10.1038/nature14660.