Figure 6. The WS genotype was maintained on agar plates at low population densities in the multiple-colony agar microcosm (MUCAM), but was rapidly lost at high population densities.

Colonies were recovered from plates every 5-days as a single population and used to inoculate fresh plates. The percentage of cells still showing the WS phenotype (WS Stability) after each 5-day period is indicated. Populations were transferred at three densities, high (H) (1,000–2,000 cfu per plate), medium (M) (100–200 cfu per plate), and low (L) (10–20 cfu per plate). Colonies were incubated on KB plates at 28°C before transfer to new plates. Mean±SE indicated.