Fig. 10.

Effect of the L. pneumophila surfactant on the growth of L. micdadei. For the two leftmost panels, we spotted dilutions of L. micdadei onto BCYE plates containing either 1.5% agar or 0.5% agar but no nearby L. pneumophila (Lp −). For the next five panels, we spotted L. micdadei onto 0.5% agar BCYE containing a nearby row of WT L. pneumophila that had grown and made a surfactant film (Lp 130b; third panel), a row of a bbcI mutant that had grown but not produced a surfactant (Lp NU389; fourth panel), a row of the complemented bbcI mutant that had restored surfactant production [Lp NU389(pMlpw_24111); fifth panel], a row of a tolC mutant that had grown but not made a surfactant (Lp NU390; sixth panel), or a row of an lspF mutant that had grown but lacked a surfactant (Lp NU275; last panel). After incubation at 37°C for another 3 days, growth of L. micdadei in the absence (Sfct −) or presence (Sfct +) of a surfactant was imaged. The results depicted here were observed in at least three independent experiments.