Cell balance equation for chemotactic bacteria with a biphasic tumbling frequency.
Alt's three-dimensional cell balance equation characterizing the chemotactic bacteria was analyzed under the presence of one-dimensional spatial chemoattractant gradients. Our work differs from that of others who have developed rather general models for chemotaxis in the use of a non-smooth anisotropic tumbling frequency function that responds biphasically to the combined temporal and spatial chemoattractant gradients. General three-dimensional expressions for the bacterial transport parameters were derived for chemotactic bacteria, followed by a perturbation analysis under the planar geometry. The bacterial random motility and chemotaxis were summarized by a motility tensor and a chemotactic velocity vector, respectively. The consequence of invoking the diffusion-approximation assumption and using intrinsic one-dimensional models with modified cellular swimming speeds was investigated by numerical simulations. Characterizing the bacterial random orientation after tumbles by a turn angle probability distribution function, we found that only the first-order angular moment of this turn angle probability distribution is important in influencing the bacterial long-term transport.
Chen
Kevin C
KC
Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4264, USA. chench@pop.nci.nih.gov
Ford
Roseanne M
RM
Cummings
Peter T
PT
D016880:Anisotropy; D018407:Bacterial Physiological Phenomena; D002630:Chemotactic Factors / Q000494:pharmacology; D002633:Chemotaxis; D003198:Computer Simulation; D008124:Locomotion; D008954:Models, Biological; D009716:Numerical Analysis, Computer-Assisted; D011336:Probability
D002630:Chemotactic Factors