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Oscillatory surface rheotaxis of swimming E. coli bacteria
Arnold J T M Mathijssen1,2, Nuris Figueroa-Morales3,4, Gaspard Junot3
1Department of Bioengineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305, USA.
Nature Communications
|August 2, 2019
Summary
Bacteria can swim upstream against flow, a phenomenon called rheotaxis. This study reveals new rheotaxis regimes in E. coli under shear flow, impacting contamination control and microswimmer navigation.
Area of Science:
- Microbiology
- Fluid Dynamics
- Biophysics
Background:
- Bacterial contamination poses significant public health risks.
- Upstream swimming (rheotaxis) amplifies contamination in channels and water resources.
- Mechanisms of bacterial rheotaxis in shear flow are poorly understood.
Purpose of the Study:
- Investigate bacterial rheotaxis mechanisms in shear flow.
- Identify critical shear rates for different rheotaxis behaviors.
- Understand bacterial navigation strategies in complex fluid environments.
Main Methods:
- 3D Lagrangian tracking of individual E. coli.
- Fluorescent flagellar labeling for visualization.
- Analysis of bacterial behavior under varying shear rates.
Main Results:
- Identified three distinct rheotaxis regimes with increasing shear rate.
- Observed upstream swimming, oscillatory rheotaxis, and bidirectional rheotaxis.
- Predicted critical shear rates for each transition using theoretical analysis.
Conclusions:
- Rheotaxis mechanisms in E. coli are shear-dependent and exhibit distinct regimes.
- Findings offer insights into bacterial transport and contamination.
- Potential applications include contamination prevention, cell sorting, and microswimmer navigation.
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