Flow environment and matrix structure interact to determine spatial competition in Pseudomonas aeruginosa biofilms
Abstract
Bacteria often live in biofilms, which are microbial communities surrounded by a secreted extracellular matrix. Here, we demonstrate that hydrodynamic flow and matrix organization interact to shape competitive dynamics in Pseudomonas aeruginosa biofilms. Irrespective of initial frequency, in competition with matrix mutants, wild type cells always increase in relative abundance in planar microfluidic devices under simple flow regimes. By contrast, in microenvironments with complex, irregular flow profiles - which are common in natural environments - wild type matrix-producing and isogenic non-producing strains can coexist. This result stems from local obstruction of flow by wild-type matrix producers, which generates regions of near-zero shear that allow matrix mutants to locally accumulate. Our findings connect the evolutionary stability of matrix production with the hydrodynamics and spatial structure of the surrounding environment, providing a potential explanation for the variation in biofilm matrix secretion observed among bacteria in natural environments.
Article and author information
Author details
Funding
Alexander von Humboldt Stiftung
- Carey D Nadell
- Bonnie Bassler
Human Frontier Science Program
- Knut Drescher
Max-Planck-Gesellschaft
- Knut Drescher
- Bonnie Bassler
Howard Hughes Medical Institute
- Bonnie Bassler
National Institutes of Health
- Bonnie Bassler
National Science Foundation
- Bonnie Bassler
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2017, Nadell et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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