Self-generated hydrogel ejects bacterial cells for localized biofilm dispersion.

Bacillus subtilis biofilms eject specific cells using a self-generated gamma-polyglutamic acid hydrogel, revealing a novel dispersion mechanism with 3D cell ejection.

• Why it matters: Understanding biofilm dispersion is crucial because it influences bacterial spread and resilience, yet the mechanisms behind cell release are poorly understood, limiting control strategies.
• What they did: The study combined high-resolution imaging, mathematical modeling, and genetic and chemical perturbations to show that gamma-polyglutamic acid production creates osmotic pressure that propels interior cells outward, enabling their ejection.
• The result: This discovery uncovers a new, controllable biofilm dispersion process driven by biofilm-produced hydrogel, paralleling mechanisms seen in marine organisms, and offers potential targets for biofilm management.