FIG. 6.

TLC analysis of lipid hydrolysis by wild-type and mutant L. pneumophila. Tenfold-concentrated culture supernatants from late log phase of strains 130b (WT), NU270 (P), and an lspDE mutant (L) were incubated with MPLPC or DPPC for 18 h at 37°C. Subsequently, the lipids were extracted and separated by TLC. A mixture of concentrated BYE broth and the lipids was also incubated and served as a negative control (N). In the case of incubations with MPLPC (left panel), the samples were examined for the degradation of the lipid substrate and, in the cases of incubations with DPPC, for enrichment of lysophosphatidylcholine (LPC). For the qualitative identification of the lipid spots, lanes containing MPLPC and DPPC standards are marked St. The observations depicted here were made on at least two occasions.