FIG. 9.
Lipolytic activities of culture supernatants of wild-type and proA mutant L. pneumophila. Culture supernatants from log-phase cultures of strains 130b and proA mutant AA200 were incubated with MPLPC, MPLPG, 1-MPG, DPPG, or DPPC for 2.5 h at 37°C. Subsequently, the release of FFA was quantified. Data are expressed as differences between the amount of FFA released by the culture supernatant versus the amount released by uninoculated BYE broth. Results represent the means ± standard deviations of four cultures and are representative of two independent experiments. Asterisks denote significant differences in lipolytic activities between wild-type L. pneumophila and the proA mutant (P < 0.05; Student's t test).