Formation and dissolution of bacterial colonies.

Area of Science:

• Physics
• Microbiology
• Biophysics

Background:

• Organisms form transient colonies to survive environmental stress.
• Bacterial biofilms are a key example, but their formation and dissolution mechanisms are poorly understood.
• Physical models are needed to explain these complex biological processes.

Purpose of the Study:

• To derive a hydrodynamic equation for bacterial colony formation and dissolution.
• To use experimental data for Neisseria gonorrhoeae to estimate kinetic coefficients.
• To model colony dynamics and understand the impact of cell interactions.

Main Methods:

• Developed a kinetic theory model for motile, interacting cells.
• Derived a hydrodynamic equation for cell density on a surface.
• Estimated kinetic coefficients using experimental data for N. gonorrhoeae.

Main Results:

• Successfully described the formation of multiple bacterial colonies with experimentally consistent sizes.
• Demonstrated that changes in cell-to-cell interactions drive colony dissolution.
• Validated the physical model's ability to capture colony dynamics.

Conclusions:

• Kinetic theory can be successfully applied to complex, far-from-equilibrium biological systems.
• The derived model provides a physical quantification of early-stage biofilm formation.
• This work opens new avenues for understanding microbial colony dynamics.