Chemotaxis when bacteria remember: drift vs diffusion

by Dr Sakuntala Chatterjee (S.N. Bose Centre for Basic Sciences, Kolkata)

Thursday 18 Oct 2012, 14:30 → 15:30 Asia/Kolkata

A304 (Colaba Campus)

Escherichia coli (E. coli) bacteria govern their trajectories by switching between running and tumbling modes as a function of the nutrient concentration they experienced in the past. In a recent study, it has been argued, using approximate analytical treatments in one dimension, that there is a conflict between the ability of the bacterium to reach regions of high nutrient concentration quickly and remaining there at long times. Here we perform numerical simulation in one-dimension and show that there is no such conflict. To understand these results we propose a coarse grained model which is shown to agree well with the numerics. Importantly, the model is significantly different from the common one used in many earlier works and which does not capture the behavior found in our numerics. The origin of the discrepancy is discussed.