Cooperation and conflict in microbial biofilms

By Joao Xavier and Kevin Foster
Foster Lab
The Bauer Laboratory at Harvard University
7 Divinity Avenue Cambridge, MA 02138, USA

Animations of some simulations presented in the article

1. Diffusion-reaction turned off: the unrealistic case with no oxygen gradients

This simulation shows the advantage of EPS- strategy in direct competition with EPS+ in the unrealistic case where oxygen concentrations are constant throughout the whole biofilm.
The outcome illustrated the importance of the naturally ocuring gradients in biofilm development

Quicktime file, 4 Mb

Conditions for simulation

• f = 0.55
• ρ_X/ρ_EPS = 6
• C_O2,env = 8mg/L (constant throughout the computational domain)

2. Simulation with EPS- win

This simulation shows a case where EPS- strategy has the advantage due to EPS high density.

Quicktime file, 4.5 Mb
[Higher quality movie - Quicktime, 44 Mb]

Conditions for simulation

• f = 1.5
• ρ_X/ρ_EPS = 0.5
• C_O2,env = 8mg/L

3. Simulation with EPS+ win

This simulation shows a case where EPS+ strategy has the advantage.

Quicktime file, 3.3 Mb
[Higher quality movie - Quicktime, 31 Mb]

Conditions for simulation

• f = 0.55
• ρ_X/ρ_EPS = 6
• C_O2,env = 8mg/L