FIG. 5.

Lipolytic activities of culture supernatants of wild-type and plaA mutant L. pneumophila. Culture supernatants from late log phase of BYE cultures of strains 130b and NU270 were incubated with MPLPC, MPLPG, 1-MPG, DPPG, or DPPC for 2.5 h at 37°C, and then the release of FFA was quantified. Data are expressed as differences between the amount of FFA released by the culture supernatant and the amount released by uninoculated BYE broth. The results represent the means ± standard deviations of triplicate cultures and are representative of two independent experiments. Asterisks denote significant differences in lipolytic activities between wild-type L. pneumophila and NU270 (P < 0.01 for MPLPC, MPLPG, DPPG, and DPPC hydrolysis, and P < 0.05 for hydrolysis of 1-MPG; Student's t test).