TABLE 2.

Diffusion coefficients estimated from analyses of swimming tracks in 10 strains of bacteria^a

Strain	No. of tumbles s−1	τ (s)	α	uavg (μm s−1)	umax (μm s−1)	Davg (cm2 s−1)	Dmax (cm2 s−1)
HP1	0.16	6.2	−0.67	21	30	2.6 × 10−6	5.7 × 10−6
HP4	0			22	26
HP5	0.096	10.5	−0.67	26	34	6.8 × 10−6	12 × 10−6
HP11	0.076	14.9	−0.67	32	51	16 × 10−6	38 × 10−6
HP15	0			29	37
HP25	Nonmotile
HP33	0.48	2.07	−0.67	22	30	1.0 × 10−6	1.9 × 10−6
HP39	0.33	3.05	−0.67	22	28	1.4 × 10−6	2.4 × 10−6
HP43	Nonmotile
HP46	2.06	0.4	0.48	28	56	0.4 × 10−6	1.4 × 10−6

^aTumbling frequencies, average run length (τ), turn angles (as α), and swimming velocities for 10 bacterial strains from analyses of swimming tracks. Two estimates of swimming velocity are provided, u_avg, which is the overall average 2-D swimming velocity multiplied by 1.22, and u_max, which is the average velocity that is sustained for long periods. A diffusion coefficient is computed for each of these velocities (D_avg and D_max, respectively).