FIG. 1.

Appearance of rpoS mutations in chemostat cultures operating at various growth rates. Chemostat cultures of strain BW2952 growing at dilution rates of 0.1, 0.3, and 0.6 h⁻¹ were monitored for the first 10 days after inoculation. Under each condition, three replicate populations were established. At the same time each day, samples were diluted in MMA, plated onto Luria agar plates, and incubated overnight at 37°C. Plates were stored at 4°C for another 24 h before being flooded with iodine to distinguish dark brown glycogen-containing cells (RpoS⁺), the proportion of which is shown in each graph. (A) Glucose-limiting cultures; (B) nitrogen-limiting cultures. Error bars indicate standard deviations.