Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.08.11.243733v1?rss=1 Authors: Grobas, I., Polin, M., Asally, M. Abstract: Swarming and biofilm formation are two modes of bacterial collective behavior that enable cells to increase their tolerance to anti-microbial stressors. Swarming is a rapid type of surface colonization, and therefore its ability to withstand high antibiotic concentrations could lead to the subsequent establishment of highly resilient biofilms in regions that could not otherwise have been colonized. However, whether swarms can transit into biofilm at all, and how, remains unclear. Using Bacillus subtilis, we reveal that a biophysical mechanism, reminiscent of motility-induced phase separation (MIPS), underpins a swarming-to-biofilm transition through a localized dynamic phase transition. Guided by the MIPS paradigm, we demonstrate that the transition is triggered by environmental stressors such as an antibiotic gradient or even a simple physical barrier. Based on the biophysical insight, we propose a promising strategy of antibiotic treatment to effectively inhibit the transition from swarms to biofilms, by targeting the localized phase transition. The biophysical origin of such a transition suggests that biophysics-based approaches could emerge as a potential tool to control and understand collective stress response in bacterial communities. Copy rights belong to original authors. Visit the link for more info