Holographic Imaging Reveals the Mechanism of Wall Entrapment in Swimming Bacteria
Self-propelled particles, both biological and synthetic, are stably trapped by walls and develop high concentration peaks over bounding surfaces. In swimming bacteria, like E. coli, the physical mechanism behind wall entrapment is an intricate mixture of hydrodynamic and steric interactions with a s...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2017-01-01
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| Series: | Physical Review X |
| Online Access: | http://doi.org/10.1103/PhysRevX.7.011010 |
| _version_ | 1818399677765124096 |
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| author | Silvio Bianchi Filippo Saglimbeni Roberto Di Leonardo |
| author_facet | Silvio Bianchi Filippo Saglimbeni Roberto Di Leonardo |
| author_sort | Silvio Bianchi |
| collection | DOAJ |
| description | Self-propelled particles, both biological and synthetic, are stably trapped by walls and develop high concentration peaks over bounding surfaces. In swimming bacteria, like E. coli, the physical mechanism behind wall entrapment is an intricate mixture of hydrodynamic and steric interactions with a strongly anisotropic character. The building of a clear physical picture of this phenomenon demands direct and full three-dimensional experimental observations of individual wall entrapment events. Here, we demonstrate that, by using a combination of three-axis holographic microscopy and optical tweezers, it is possible to obtain volumetric reconstructions of individual E. coli cells that are sequentially released at a controlled distance and angle from a flat solid wall. We find that hydrodynamic couplings can slow down the cell before collision, but reorientation only occurs while the cell is in constant contact with the wall. In the trapped state, all cells swim with the average body axis pointing into the surface. The amplitude of this pitch angle is anticorrelated to the amplitude of wobbling, thus indicating that entrapment is dominated by near-field couplings between the cell body and the wall. Our approach opens the way to three-dimensional quantitative studies of a broad range of fast dynamical processes in motile bacteria and eukaryotic cells. |
| first_indexed | 2024-12-14T07:24:29Z |
| format | Article |
| id | doaj.art-b3cdd36c586445d19717190cdcedb297 |
| institution | Directory Open Access Journal |
| issn | 2160-3308 |
| language | English |
| last_indexed | 2024-12-14T07:24:29Z |
| publishDate | 2017-01-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review X |
| spelling | doaj.art-b3cdd36c586445d19717190cdcedb2972022-12-21T23:11:32ZengAmerican Physical SocietyPhysical Review X2160-33082017-01-017101101010.1103/PhysRevX.7.011010Holographic Imaging Reveals the Mechanism of Wall Entrapment in Swimming BacteriaSilvio BianchiFilippo SaglimbeniRoberto Di LeonardoSelf-propelled particles, both biological and synthetic, are stably trapped by walls and develop high concentration peaks over bounding surfaces. In swimming bacteria, like E. coli, the physical mechanism behind wall entrapment is an intricate mixture of hydrodynamic and steric interactions with a strongly anisotropic character. The building of a clear physical picture of this phenomenon demands direct and full three-dimensional experimental observations of individual wall entrapment events. Here, we demonstrate that, by using a combination of three-axis holographic microscopy and optical tweezers, it is possible to obtain volumetric reconstructions of individual E. coli cells that are sequentially released at a controlled distance and angle from a flat solid wall. We find that hydrodynamic couplings can slow down the cell before collision, but reorientation only occurs while the cell is in constant contact with the wall. In the trapped state, all cells swim with the average body axis pointing into the surface. The amplitude of this pitch angle is anticorrelated to the amplitude of wobbling, thus indicating that entrapment is dominated by near-field couplings between the cell body and the wall. Our approach opens the way to three-dimensional quantitative studies of a broad range of fast dynamical processes in motile bacteria and eukaryotic cells.http://doi.org/10.1103/PhysRevX.7.011010 |
| spellingShingle | Silvio Bianchi Filippo Saglimbeni Roberto Di Leonardo Holographic Imaging Reveals the Mechanism of Wall Entrapment in Swimming Bacteria Physical Review X |
| title | Holographic Imaging Reveals the Mechanism of Wall Entrapment in Swimming Bacteria |
| title_full | Holographic Imaging Reveals the Mechanism of Wall Entrapment in Swimming Bacteria |
| title_fullStr | Holographic Imaging Reveals the Mechanism of Wall Entrapment in Swimming Bacteria |
| title_full_unstemmed | Holographic Imaging Reveals the Mechanism of Wall Entrapment in Swimming Bacteria |
| title_short | Holographic Imaging Reveals the Mechanism of Wall Entrapment in Swimming Bacteria |
| title_sort | holographic imaging reveals the mechanism of wall entrapment in swimming bacteria |
| url | http://doi.org/10.1103/PhysRevX.7.011010 |
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