Modeling the motion of E.coli in colonies of different cellular densities: A transition from swimming to swarming

D. HANSMANN; G. FIER; R.C BUCETA

Los Reyunos, San Rafael (Mendoza)

Congreso; Congreso; TREFEMAC 2015 - 13° Congreso Regional de Física Estadística y Aplicaciones a la Materia Condensada; 2015; 2015

UTN (San Rafael) - ANPCyT - CONICET

E.coli is a microorganism capable of moving individually (swimming) and collectively (swarming). Since decades its individual movement is subject of extensive studies and many aspects of its swimming behavior have been characterized. In addition to this on-going research, more recently E.coli?s collective behavior became the focus of attention of many investigations in the fields of biology and physics. Authors working with E.coli colonies observe that bacteria which prepare for swarming undergo remarkable physical changes like length growth and hyper flagellation. The obvious differences between the dynamics swarmer colonies and swimmer colonies lead to the conclusion that these individual physical transformations go together with a difference in the individual bacterial motility (behavior). In this work we address the question of individual bacterial dynamics in swarming colonies, concerning the well-known swimming motility called ?Run and Tumble?. We present a model of self-propelled rigid bodies that simulates swimming E.coli. aiming to reproduce experimentally obtained statistical observables as close as possible. Using our swimming model we study the transition from bacterial swimming to bacterial swarming in base of simple, short range rigid body interactions. To this end we increase the agent density of our sample and raise the individual driving force of the agents. The results of the simulation are compared with experimental data and are discussed in a theoretical and experimental context.