Abstract

Timelapse microscopy is a largely used technique for studying microbes, and especially rod-shaped bacteria like the model organism E. coli. However, so far, the mechanics of growth of these organisms in such conditions have not been investigated. Moreover, in a physiological prospective, interfaces are privileged areas where bacteria can settle sessile colonies structured in biolms. Addressing the question of the morphogenesis in early stage of the colony development may give us some hints of how bacteria manage to optimize a balance between the access to environmental resources and the cell-cell interactions. By performing laser ablation and traction force microscopy on growing micro-colonies, we showed that there is an asymmetric adhesion between the pre-existing and the newly formed poles of the bacteria. This drives the transition from a rod-shaped bacteria with a strong linear symmetry to a two-dimensional the micro-colony. By measuring stresses developed by different micro-organisms, we are starting to get an insight of how these mechanical forces play a role in the whole colony shaping.