Collective self-caging of active filaments in virtual confinement.

Area of Science:

• Microbiology
• Biophysics
• Soft Matter Physics

Background:

• Microorganisms use motility and behavioral responses to find suitable habitats.
• Filamentous cyanobacteria exhibit reversals in motion, aiding aggregation and habitat selection.
• Understanding these behaviors is key to comprehending microbial colony formation.

Purpose of the Study:

• To investigate the consequences of light-gradient-responsive reversals in filamentous cyanobacteria.
• To explore how light patterns, specifically boundary curvature, influence aggregate formation.
• To model the emergent properties of active flexible filaments in response to light.

Main Methods:

• Experimental observation of filamentous cyanobacteria in controlled light gradients.
• Analysis of aggregate formation at illuminated region boundaries.
• Development of a minimal mechanistic model of active flexible filaments.

Main Results:

• Filamentous cyanobacteria form entangled aggregates at the boundaries of illuminated regions.
• Aggregate formation is influenced by the curvature of light pattern boundaries.
• A minimal model successfully replicates experimental findings, highlighting emergent properties.

Conclusions:

• Filamentous morphology and light-responsive reversals lead to emergent ordered structures at light boundaries.
• This phenomenon allows microorganisms to generate adaptive colony architectures.
• The findings have implications for biomimetic fibrous material assembly.