Beecroft Building, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Professor Albane Théry, University of Warwick
Abstract
Selenonomas sputigena is an oral pathogen that can cause severe co-infections and rapid tooth loss in children, but from a physics perspective, it is a helical bacterium that swims with fifteen flagella stemming from a bundle placed on the subpolar side of its body. All of these characteristic (body shape, number of flagella, position of the bundle) puzzled us greatly when we started describing their motility patterns and led us to new questions about the relationships between flagellar location, cell shape and swimming environments. I will present some of answers to these using an elasto-hydrodynamic model to study their coupling, including regimes where buckling and large deformations of the flagellum occur. Large mechanical deformations—such as twisting and knot formation—also arise at the collective scale. I will show how similar modelling approaches can inform our understanding of filamentous cyanobacteria, which form long active filaments of hundreds of cells, and can form macroscale transient, motile aggregates that can collect passive particles in their surroundings. I will discuss how models and simulations, here coupling elasticity, fluid mechanics and active particles, can inform our understanding of microbiology experiments, and their consequence for biomedical and ecological applications.
This is joint work with Zhi Ren (University of Pennsylvania Dental School) and Rebecca Poon and Orkun Soyer (Warwick School of Life Sciences).