Self-buckling and self-writhing of semi-flexible microorganisms
| Autor: | Lough, Wilson, Weibel, Douglas B., Spagnolie, Saverio E. |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Soft Matter (2023) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1039/d3sm00572k |
| Popis: | The twisting and writhing of a cell body and associated mechanical stresses is an underappreciated constraint on microbial self-propulsion. Multi-flagellated bacteria can even buckle and writhe under their own activity as they swim through a viscous fluid. New equilibrium configurations and steady-state dynamics then emerge which depend on the organism's mechanical properties and on the oriented distribution of flagella along its surface. Modeling the cell body as a semi-flexible Kirchhoff rod and coupling the mechanics to a dynamically evolving flagellar orientation field, we derive the Euler-Poincar{\'e} equations governing dynamics of the system, and rationalize experimental observations of buckling and writhing of elongated swarmer cells of the bacterium {\it Proteus mirabilis}. A sequence of bifurcations is identified as the body is made more compliant, due to both buckling and torsional instabilities. These studies highlight a practical requirement for the stiffness of bacteria below which self-buckling occurs and cell motility becomes ineffective. Comment: 7 pages, 3 figures |
| Databáze: | arXiv |
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