From single cells to filaments: a dance of geometry and motion
In recent years, biological motile cells like bacteria and microalgae have attracted considerable interest
not only among biologists but also in the physics community and related fields. Understanding their
motion has immense biological and ecological implications. The possibility to harness their motion to
power microdevices is a topic of exceptional importance for modern microtechnology. When the motion
of a microscopic organism is observed closely, it appears erratic, and yet the combination of
nonequilibrium forces and surfaces can produce striking examples of organization in microbial systems.
Combining experiments, analytical and numerical calculations [1,2] we study the motion of motile cells
under controlled lab conditions and demonstrate that intricate patterns can be observed from the level
of a single cell exploring an isolated habitat to an entire colony. We consider two model organisms. In
the first part of this talk, we will discuss the influence of boundaries on the motion of a single
Chlamydomonas cell. We theoretically predict a universal relation between probability fluxes and
global geometric properties that is directly confirmed by experiments [2]. Our results represent a general
description of the structure of such nonequilibrium fluxes down at the single cell level. This might open
the possibility of designing devices that are able to guide the motion of such microbial cells. In the
second part of this talk, we will discuss recent results on colonies of cyanobacteria, their pattern
formation and order-disorder transition.
[1] J. Cammann, et al., Proc. Natl. Acad. Sci. 118, e2024752118 (2021).
[2] T. Ostapenko, et al, Phys. Rev. Lett. 120, 068002 (2018).
Jan Cammann
Interdisciplinary Centre for Mathematical Modelling, Loughborough University, UK.
Jan Cammann completed Bachelor and Master in Physics degrees from the Georg August University of
Göttingen, Germany between 2013 – 2016 and 2016 – 2019 respectively, while working at the Max
Planck Institute for Dynamics and Self-Organization. Currently, Jan is a doctoral student working on
microbial motility at the Interdisciplinary Centre for Mathematical Modelling at Loughborough
University, UK under supervision of Dr. Marco G. Mazz