Bacterial Chemotaxis (Run-and-Tumble)
Parameters
Bacteria (N):
60
Run speed:
2.0
Base tumble rate (λ₀):
0.05
Chemo-sensitivity (χ):
3.0
Attractant source:
Center
Corner
Uniform gradient
Two sources
Run
Reset
Running:
—
Near source:
—
%
Avg drift:
—
Run-and-tumble:
E. coli swims straight (run), then randomly reorients (tumble). Chemotaxis: suppress tumbling when moving up-gradient.
λ(grad) = λ₀ · exp(−χ · ∇c/c). Color: green=running, red=tumbling.
Drift velocity ≈ χ·v²/(6λ₀) · |∇ln c|.