Figure 4. Starvation sensitivity of a PPS-deficient mutant.

1. The prcSBA operon.
2. Western blot analysis using anti-Pup and anti-20Sα antibodies, as indicated.
3. Exponentially growing cultures were diluted into fresh media, and turbidity was measured (n = 3) at the indicated time points.
4. Exponentially growing cultures were diluted into fresh media (day 0), and samples were collected during the exponential phase at day 18. All samples were diluted to an OD₆₀₀ of 0.5, serial dilutions were carried out, and 10 μl of the indicated dilutions were plated on solid media.
5. The concentration of live cells in 17-day-old liquid cultures was determined via colony counts (n = 3) following sample plating on solid media.