Figure 5. The WS genotype was maintained on agar plates at low population densities in the mega-colony agar microcosm (MEGAM) experiment, but was rapidly lost at high population densities.

The mega-colony was recovered from plates every 2 or 4-days and used to inoculate fresh plates with a single 5 µl drop (a third set of populations was incubated for 8-days without transfer). The percentage of cells still showing the WS phenotype (WS Stability) after each period is indicated. Populations were transferred at three densities, high (H) (∼10⁷ cfu per drop), medium (M) (∼10⁴ cfu per drop), and low (L) (∼10 cfu per drop). Colonies were incubated on KB plates at 28°C before transfer to new plates. Mean±SE indicated.