title: Flow environment and matrix structure interact to determine spatial competition inPseudomonas aeruginosabiofilms.
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 inPseudomonas aeruginosabiofilms. 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.
authors.affiliation: Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
authors.forename: Carey D
authors.initials: CD
authors.lastname: Nadell
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, United States.
authors.forename: Deirdre
authors.initials: D
authors.lastname: Ricaurte
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, United States.
authors.forename: Jing
authors.initials: J
authors.lastname: Yan
authors.affiliation: Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
authors.forename: Knut
authors.initials: K
authors.lastname: Drescher
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, United States.|Howard Hughes Medical Institute, Chevy Chase, United States.
authors.forename: Bonnie L
authors.identifier: 0000-0002-0043-746X
authors.initials: BL
authors.lastname: Bassler
mesh_terms: D018441:Biofilms; D004777:Environment; D056265:Microbial Interactions; D044085:Microfluidics; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000502:physiology*
keywords: Pseudomonas aeruginosa; biofilm; cooperation; ecology; evolution; flow; infectious disease; matrix; microbiology