Biophysical Society Thematic Meeting | Riga 2026

Active and Responsive Soft Matter: From Biological to Engineered Systems

Tuesday Speaker Abstracts

FLOW INDUCED STIFFENING IN EXTENSILE ACTIVE MATTER Daniel Blair 1 ; 1 Georgetown University, Washington, DC, USA

No Abstract

JUST KEEP SWIMMING: STRUCTURAL ADAPTATIONS IN VIBRIO SPECIES FOR NAVIGATION IN COMPLEX ENVIRONMENTS Marianne Grognot 1 ; 1 RWTH Aachen University, Institute of Medical Microbiology, Aachen, Germany About half of bacterial pathogens can swim by rotating one or more flagella. Motility and chemotaxis (altogether termed navigation) can improve processes such as survival, dispersal or infection. Yet most navigation studies concentrate on E. coli in buffe r, overlooking the diverse strategies employed by other species in more realistic, complex habitats. This talk offers a quantitative dive into the motility and chemotaxis of two Vibrio species with a polar flagellum and distinct adaptive morphologies linked with virulence: Vibrio cholerae can increase its cell body curvature while Vibrio alginolyticus can express an additional set of lateral flagella. Using a multiscale chemotaxis assay leveraging high-throughput 3D tracking [1] , we quantified their navigation performances in buffer, soft agar hydrogels, and viscous polymer solutions (PVP).In simple buffer, V. cholerae’s curvature had little effect on navigation (compared to its straight shape), while V. alginolyticus’ lateral flagella significantly decreased swimming speed and chemotactic performances (compared to its polar-flagellum-only phenotype). In agar hydrogels both body-curvature and lateral flagella improved swim extents between traps/stalls in the hydrogels’ mesh, near doubling their chemotactic performances. In non-Newtonian PVP, lateral flagella also improved swimming speed and chemotaxis of V. alginolyticus while cell-body curvature of V. cholerae did not. Notably, expression of lateral flagella incurred a significant growth rate penalty, whereas curvature had no such cost. Altogether, these works [2][3] suggest a fascinating and complex landscape of bacterial adaptation where cell-body curvature and lateral flagella are two examples of distinct adaptive strategies for improving bacterial navigation in complex environments. References[1] Grognot & Taute, Commun. Biol., 2021.[2] Grognot et al., "Physiological adaptation in flagellar architecture improves Vibrio alginolyticus chemotaxis in complex environments", PNAS, 2023.[3] Malik et al., "Cell-body curvature modulates stall frequency to enhance Vibrio cholerae swimming and chemotaxis through hydrogels", available on bioRxiv.

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