Abstract

E.coli bacteria have been observed to show super-diffusive motion in absence of chemical gradients. Super-diffusion is a very effective search strategy in sparse environments and thus can give E. coli evolutionary advantage. Interestingly, the super-diffusive behaviour seems to arise from stochastic fluctuations in the concentration level of an enzyme regulating the chemotactic response. In this talk I will give a short introduction to anomalous diffusion and show, how super-diffusion can be derived from a continuous-time random walk model. Subsequently, I will present a mathematical model of the E. coli chemotaxis signalling pathway where additive noise can lead to a transition from classical to anomalous diffusion. Simulations of larger populations in different chemical landscapes will present a basis to discuss the benefits and drawbacks of this noise-induced behaviour.