Abstract
Adhesion forces due to active pili govern the formation of biofilms by a wide range of bacteria. Using simulations, this work shows how such active adhesions determine the morphology of bacterial collectives, their non-equilibrium fluctuations, and the spreading dynamics in different geometries. Colonies of bacteria endowed with a pili-based self-propulsion machinery are ideal models for investigating the structure and dynamics of active many-particle systems. We study Neisseria gonorrhoeae colonies with a molecular-dynamics-based approach. A generic, adaptable simulation method for particle systems with fluctuating bond-like interactions is devised. The simulations are employed to investigate growth of bacterial colonies and the dependence of the colony structure on cell-cell interactions. In colonies, pilus retraction enhances local ordering. For colonies consisting of different types of cells, the simulations show a segregation depending on the pili-mediated interactions among different cells. These results agree with experimental observations. Next, we quantify the power-spectral density of colony-shape fluctuations in silico. Simulations predict a strong violation of the equilibrium fluctuation-response relation. Furthermore, we show that active force generation enables colonies to spread on surfaces and to invade narrow channels. The methodology can serve as a foundation for future studies of active many-particle systems at boundaries with complex shape.
Dokumententyp: | Zeitschriftenartikel |
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Fakultät: | Tiermedizin > Veterinärwissenschaftliches Department |
Themengebiete: | 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit |
ISSN: | 2399-3650 |
Sprache: | Englisch |
Dokumenten ID: | 110807 |
Datum der Veröffentlichung auf Open Access LMU: | 02. Apr. 2024, 07:20 |
Letzte Änderungen: | 02. Apr. 2024, 07:20 |