Table 2. Doubling time comparisons in 0.5 % (top) and 2.5 % (bottom) tryptone soft agar plates.

Apparent growth rate*	CAT_KmR	CAT_IS5	Emerging mutants
Maximal (0.5 % tryptone; 1–15 h)	62	49	65
Average (0.5 % tryptone; 15–25 h)	288	866	60
Maximal (2.5 % tryptone; 1–15 h)	57	47	60
Average (2.5 % tryptone; 15–25 h)	238	492	56

*Doubling times for CAT_Km^R (wild-type), CAT_IS5 and emerging insertion mutants in 0.5 % tryptone soft agar plates (top) and 2.5 % tryptone soft agar plates (bottom). The maximal growth rate for the 1–15 h interval was the steepest slope before the 15 h time point, and the apparent average growth rate for the subsequent time period was the slope between 15 and 25 h. Values are expressed in minutes (min). Note that the values for the emerging mutants represent a sum of their appearance rates and their growth rates, with the former presumably predominating.