Abstract

Swimming bacteria with helical flagella are self-propelled micro-swimmers in nature, and the swimming strategies of such bacteria vary depending on the number and the position of flagella embedded in the cell body. In this talk, I will introduce two types of microorganisms, multi-flagellated E. coli and single-flagellated Vibrio A., and focus on how bacteria can swim and reorient their swimming course for survival. To model the fluid-cell interaction, the model organism consists of a rigid spheroidal cell body and a flexible single or multiple helical flagella attached to the cell body. The Kirchhoff rod theory is used to describe the elastic helical flagella and the cell body is represented by a hollow ellipsoid that can translate and rotate as a neutrally buoyant body interacting with a surrounding fluid. The hydrodynamic interaction between the fluid and the cell is described by the regularized version of Stokes flow. Mathematical approaches developed in this work can help to understand the swimming mechanism of flagellated bacteria.