Bacteria such as Escherichia coli and Salmonella typhimurium swim through a fluid by rotating their helical flagella. Understanding the swimming mechanism of bacteria with flagella is a challenging subject that involves interactions between the biological, engineering, mathematical, and physical sciences. Although many scientists have studied bacterial swimming, experimental and theoretical studies have both shown that it is difficult to understand the dynamic behavior of the flagellum because of its complex geometry during locomotion, and many open questions remain. This project will develop and validate improved mathematical models for such bacterial motility.
The goals of this project are to: (1) develop detailed mathematical models accompanied by the numerical schemes to understand bacterial motility by means of flagella; (2) analyze the complicated hydrodynamic interactions among multiple flagella arising from the cell body in fluids; (3) validate the models by comparing the results to experimental data; and (4) use these models to make predictions that will be verified by further experimentation. This project also heavily involves the development of an adaptive version of the generalized immersed boundary method which will find numerous applications in biological fluid dynamics such as supercoiling DNA dynamics. The new numerical algorithm will be freely distributed on-line within IBAMR software. The results obtained from this research on free swimming bacteria may provide new information about the spread of infections and biofilm formation, and may help to design nanomachines that are self-propelled by flagella.