A Theoretical Study of Receptor Mechanisms in Bacterial Chemotaxis

Equations are formulated that link the probability of a bacterium suddenly changing its direction with temporal change in the number of attractant molecules that are bound to the bacteria’s receptor molecules. “Memory” arising from the noninstantaneous nature of the attractant-receptor chemical reaction is taken into account in this one-dimensional model by considering separate populations of left- and right-moving bacteria. Previously formulated phenomenological equations for bacterial chemotaxis are recovered when a perturbation analysis is permitted by sufficiently shallow gradients. A detailed comparison is provided with certain relevant experiments.