Failed Escape: Solid Surfaces Prevent Tumbling of Escherichia coli

• Main Authors: Molaei, Mehdi (Author), Barry, Michael (Contributor), Stocker, Roman (Contributor), Sheng, Jian (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Civil and Environmental Engineering (Contributor), Parsons Laboratory for Environmental Science and Engineering (Massachusetts Institute of Technology) (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2014-08-11T17:41:52Z.
• Subjects: Article
• Online Access: Get fulltext

Understanding how bacteria move close to surfaces is crucial for a broad range of microbial processes including biofilm formation, bacterial dispersion, and pathogenic infections. We used digital holographic microscopy to capture a large number (>10[superscript 3]) of three-dimensional Escherichia coli trajectories near and far from a surface. We found that within 20  μm from a surface tumbles are suppressed by 50% and reorientations are largely confined to surface-parallel directions, preventing escape of bacteria from the near-surface region. A hydrodynamic model indicates that the tumble suppression is likely due to a surface-induced reduction in the hydrodynamic force responsible for the flagellar unbundling that causes tumbling. These findings imply that tumbling does not provide an effective means to escape trapping near surfaces.
National Institutes of Health (U.S.) (Grant 1-R21-EB008844-01)
National Science Foundation (U.S.) (Grant OCE-0744641-CAREER)
National Science Foundation (U.S.) (Grant CBET-1066566)