FIGURE 2.

Growth-dependent incorporation of glucose or serine into L. pneumophila grown in liquid culture. A, schematic growth curve of L. pneumophila in AYE medium at 37 °C for the indicated periods of ¹³C labeling (EE, LE, PE, and S). B, ¹³C enrichments of amino acids and PHB of L. pneumophila Paris WT grown in AYE medium at 37 °C during various growth phases (EE, LE, PE, and S) using [U-¹³C₆]glucose or [U-¹³C₃]serine as precursors, respectively. Overall ¹³C excess (mol %) of labeled amino acids and PHB is given by a color map in a quasilogarithmic form to show even relatively small ¹³C excess values. PHB indicated by white boxes could not be measured. Each sample (from individual labeling experiments indicated by a–r) was measured three times; the color for each amino acid correlates with the mean value of the three measurements. Arrows on top of the color code indicate the change in the relative incorporation rates during the growth phases. C, corresponding labeling data for the Δketo mutant devoid of Lpp1788, a putative key enzyme in providing the 3-hydroxybutyryl-CoA precursor for PHB biosynthesis.