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Pearce P, Song B, Skinner DJ, Mok R, Hartmann R, Singh PK, Jeckel H, Oishi JS, Drescher K, Dunkel J. Flow-Induced Symmetry Breaking in Growing Bacterial Biofilms. Phys Rev Lett 2019; 123:258101. [PMID: 31922766 DOI: 10.1103/physrevlett.123.258101] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Indexed: 06/10/2023]
Abstract
Bacterial biofilms represent a major form of microbial life on Earth and serve as a model active nematic system, in which activity results from growth of the rod-shaped bacterial cells. In their natural environments, ranging from human organs to industrial pipelines, biofilms have evolved to grow robustly under significant fluid shear. Despite intense practical and theoretical interest, it is unclear how strong fluid flow alters the local and global architectures of biofilms. Here, we combine highly time-resolved single-cell live imaging with 3D multiscale modeling to investigate the mechanisms by which flow affects the dynamics of all individual cells in growing biofilms. Our experiments and cell-based simulations reveal three quantitatively different growth phases in strong external flow and the transitions between them. In the initial stages of biofilm development, flow induces a downstream gradient in cell orientation, causing asymmetrical dropletlike biofilm shapes. In the later developmental stages, when the majority of cells are sheltered from the flow by the surrounding extracellular matrix, buckling-induced cell verticalization in the biofilm core restores radially symmetric biofilm growth, in agreement with predictions of a 3D continuum model.
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Affiliation(s)
- Philip Pearce
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge Massachusetts 02139-4307, USA
| | - Boya Song
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge Massachusetts 02139-4307, USA
| | - Dominic J Skinner
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge Massachusetts 02139-4307, USA
| | - Rachel Mok
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge Massachusetts 02139-4307, USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
| | - Raimo Hartmann
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Praveen K Singh
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Hannah Jeckel
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- Department of Physics, Philipps-Universität Marburg, 35043 Marburg, Germany
| | - Jeffrey S Oishi
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge Massachusetts 02139-4307, USA
- Department of Physics, Bates College, Lewiston, Maine 04240, USA
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- Department of Physics, Philipps-Universität Marburg, 35043 Marburg, Germany
| | - Jörn Dunkel
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge Massachusetts 02139-4307, USA
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Abstract
Controlling and suppressing bacterial accumulation at solid surfaces is essential for preventing biofilm formation and biofouling. Whereas various chemical surface treatments are known to reduce cell accumulation and attachment, the role of complex surface geometries remains less well understood. Here, we report experiments and simulations that explore the effects of locally varying boundary curvature on the scattering and accumulation dynamics of swimming Escherichia coli bacteria in quasi-two-dimensional microfluidic channels. Our experimental and numerical results show that a concave periodic boundary geometry can decrease the average cell concentration at the boundary by more than 50% relative to a flat surface.
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Affiliation(s)
- Rachel Mok
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, USA
- Department of Mathematics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, USA
| | - Jörn Dunkel
- Department of Mathematics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, USA
| | - Vasily Kantsler
- Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom
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Hartmann R, Singh PK, Pearce P, Mok R, Song B, Díaz-Pascual F, Dunkel J, Drescher K. Emergence of three-dimensional order and structure in growing biofilms. Nat Phys 2019; 15:251-256. [PMID: 31156716 PMCID: PMC6544526 DOI: 10.1038/s41567-018-0356-9] [Citation(s) in RCA: 142] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 10/19/2018] [Indexed: 05/22/2023]
Abstract
Surface-attached bacterial biofilms are self-replicating active liquid crystals and the dominant form of bacterial life on earth (1-4). In conventional liquid crystals and solid-state materials, the interaction potentials between the molecules that comprise the system determine the material properties. However, for growth-active biofilms it is unclear whether potential-based descriptions can account for the experimentally observed morphologies, and which potentials would be relevant. Here, we overcame previous limitations of single-cell imaging techniques (5,6) to reconstruct and track all individual cells inside growing three-dimensional (3D) biofilms with up to 10,000 individuals. Based on these data, we identify, constrain, and provide a microscopic basis for an effective cell-cell interaction potential, which captures and predicts the growth dynamics, emergent architecture, and local liquid crystalline order of Vibrio cholerae biofilms. Furthermore, we show how external fluid flows control the microscopic structure and 3D morphology of biofilms. Our analysis implies that local cellular order and global biofilm architecture in these active bacterial communities can arise from mechanical cell-cell interactions, which cells can modulate by regulating the production of particular matrix components. These results establish an experimentally validated foundation for improved continuum theories of active matter and thereby contribute to solving the important problem of controlling biofilm growth.
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Affiliation(s)
- Raimo Hartmann
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg,
DE
- Department of Physics, Philipps-Universität Marburg, 35032
Marburg, DE
| | - Praveen K. Singh
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg,
DE
| | - Philip Pearce
- Department of Mathematics, Massachusetts Institute of Technology,
Cambridge, MA 02139, USA
| | - Rachel Mok
- Department of Mathematics, Massachusetts Institute of Technology,
Cambridge, MA 02139, USA
- Department of Mechanical Engineering, Massachusetts Institute of
Technology, Cambridge, MA 02139, USA
| | - Boya Song
- Department of Mathematics, Massachusetts Institute of Technology,
Cambridge, MA 02139, USA
| | | | - Jörn Dunkel
- Department of Mathematics, Massachusetts Institute of Technology,
Cambridge, MA 02139, USA
- Correspondence to: ;
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg,
DE
- Department of Physics, Philipps-Universität Marburg, 35032
Marburg, DE
- Correspondence to: ;
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