Table 1. Colony expansion swarming rates of wild-type and IS mutants with and without glucose*.

	Swarming rate (mm h−1)
Strains	Without glucose	With glucose	Ratio
IS1(−469 rev)	2.20	3.60	1.6
IS1(−415 dir)	2.50	3.90	1.6
IS1(−214 rev)	2.75	3.83	1.4
IS1(−180 rev)	2.80	3.92	1.4
IS1(−120 rev)	2.90	4.35	1.5
IS1(−107 rev)	3.05	4.30	1.4
IS3(−199 rev)	2.70	4.20	1.5
IS5(−318)	2.40	3.80	1.6
IS5(−318 rev)	2.30	3.90	1.7
IS5(−169)	2.35	3.80	1.7
IS5(−169 rev)	2.50	3.90	1.6
IS5(−99)	2.70	4.20	1.5
IS5(−99 rev)	2.60	4.10	1.5
BW25113 (wild-type)†	1.14	0.50	0.4
CAT (wild-type)†	1.00	0.40	0.4

*The diameters of the swarming zones were measured in soft agar plates (0.5 % tryptone, 0.5 % NaCl and 0.3 % agar) with or without 0.5 % glucose. Each strain was grown in a liquid medium for 10–12 h before inoculation, and 1.5 µl of diluted culture was inserted into the soft agar in the middle of the plates. The plates were incubated at room temperature. The diameters of the swarms were measured every 2 h to calculate the swarming rates (mm h⁻¹), n=3. The three determinations were averaged. The error, expressed in sd of these determinations, was <0.4 mm h⁻¹.

†The sizes of the colonies were measured for wild-type and CAT (wild-type) instead of the swarming zone because of their minimal motility. Thus, the ratio±glucose represents a maximal value.