Comparison between observation and boundary element analysis for bacterium swimming motion

Abstract

In the present study, we observed motion of the bacterium, Vibrio aginolyticu, which swims rotating a single flagellum, using a dark-field microscope with a CCD camera system. Then, we took measurements of the speed and the rotation rate as well as the size of the individual bacteria. Also, we employed the boundary element method to analyze the bacterium motion and predicted the swimming speed. Then, we compared the predicted speed with the observed one. They agree well qualitatively and quantitatively. Furthermore, we evaluated the torque of the flagellar motor coupling the computational and the experimental results. It is estimated at the order of 0.1∼1 pNμm.