Models of Self-Organizing Bacterial Communities and Comparisons with Experimental Observations

A. Marrocco¹, H. Henry², I. B. Holland³, M. Plapp², S. J. Séror³ and B. Perthame^1,4*

¹ INRIA Paris-Rocquencourt, BANG, BP105, F78153 LeChesnay cedex
² Physique de la Matière Condensée, École Polytechnique, CNRS, F-91128 Palaiseau
³ Institut de Génétique et Microbiologie, CNRS UMR 8621, Univ. Paris-Sud, F-91405 Orsay
⁴ Univ. Pierre et Marie Curie, Laboratoire J.-L. Lions, CNRS UMR 7598

^* Corresponding author. E-mail: benoit.perthame@upmc.fr

Abstract

Bacillus subtilis swarms rapidly over the surface of a synthetic medium creating remarkable hyperbranched dendritic communities. Models to reproduce such effects have been proposed under the form of parabolic Partial Differential Equations representing the dynamics of the active cells (both motile and multiplying), the passive cells (non-motile and non-growing) and nutrient concentration. We test the numerical behavior of such models and compare them to relevant experimental data together with a critical analysis of the validity of the models based on recent observations of the swarming bacteria which show that nutrients are not limitating but distinct subpopulations growing at different rates are likely present.