Frequency-Dependent Escherichia coli Chemotaxis Behavior
Abstract
We study Escherichia coli chemotaxis behavior in environments with spatially and temporally varying attractant sources by developing a unique microfluidic system. Our measurements reveal a frequency-dependent chemotaxis behavior. At low frequency, the E. coli population oscillates in synchrony with the attractant. In contrast, in fast-changing environments, the population response becomes smaller and out of phase with the attractant waveform. These observations are inconsistent with the well-known Keller-Segel chemotaxis equation. A new continuum model is proposed to describe the population level behavior of E. coli chemotaxis based on the underlying pathway dynamics. With the inclusion of a finite adaptation time and an attractant consumption rate, our model successfully explains the microfluidic experiments at different stimulus frequencies.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 2012
- DOI:
- 10.1103/PhysRevLett.108.128101
- Bibcode:
- 2012PhRvL.108l8101Z
- Keywords:
-
- 87.17.Jj;
- 87.17.Aa;
- 87.18.Mp;
- 87.18.Vf;
- Cell locomotion;
- chemotaxis and related directed motion;
- Theory and modeling;
- computer simulation;
- Signal transduction networks;
- Systems biology