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BP: Fachverband Biologische Physik

BP 17: Microswimmers (joint DY/BP)

BP 17.1: Talk

Tuesday, April 1, 2014, 09:30–09:45, ZEU 146

Aftrican trypanosomes swim faster in small capillaries and heterogeneous environment — •Davod Alizadehrad and Holger Stark — Institut für Theoretische Physik, Technische Universität Berlin, Germany

Human African trypanosome (HAT), the causative agent of the deadly sleeping sickness in sub-Saharan Africa, is a protozoan or single- celled microorganism that propels itself with the help of a beating flagellum. Despite good recent progress [1], refined models and further numerical simulations are necessary to uncover the heavily debated propulsion mechanism of the trypanosome, in particular, how the flagellum is attached to the cell body.

In this study, to simulate the swimming trypanosome, we construct a refined elastic network model of trypanosome based on experimental data and combine it with the mesoscale simulation technique called multi-particle collision dynamics (MPCD) to model the fluid environment. We reproduce several key features of trypanosome motility. First, we simulate the swimming and rotation speed of the trypanosome and find excellent agreement with experiments [2]. Second, we show that confinement has profound effects on trypanosome locomotion. In narrow circular channels the swimming speed increases up to 6 times its bulk value. Finally, we demonstrate that randomly distributed obstacles in a fluid help the trypanosome to swim more efficient.

[1] S.B. Babu and H. Stark, New J. Phys. 14, 085012 (2012).

[2] N. Heddergott, et al., PLoS Pathog, 8, e1003023 (2012).