Fig. 7.

PHB in the L. pneumophila wild type and bbcB, bbcI, tolC, and lspF mutants. WT 130b, bbcB mutant NU388, bbcI mutant NU389, tolC mutant NU390, lspF mutant NU275, and complemented NU275(pMF) were grown in BYE to early log phase. The cells were then subcultured into CDM and grown at 37°C. After staining with Nile red, fluorescence was measured using a spectrophotometer blanked with unstained bacteria. Data are the means and standard deviations for three replicates obtained from duplicate cultures. The levels of PHB exhibited by the NU275 mutant were significantly increased compared to those for the other strains (P < 0.05, Student's t test). The results shown here are representative of at least four independent experiments.