Figure 2.
Effect of purified Rpf on M. luteus. (A) Resuscitation of dormant cells with different concentrations of Rpf. 10 μl of a diluted suspension of starved cells (cfu 3 × 106 cells/ml, total count 5 × 109 cells/ml) was added to 200 μl of LMM supplemented with 0.5% wt/vol l-lactate and 0.05% yeast extract and Rpf at the concentrations shown in 5–10 replicates in the Bioscreen instrument. For details see Materials and Methods. (B) Growth of washed cells. Stationary phase cells of M. luteus grown in LMM were washed 5 times by suspension and centrifugation in LMM from which lactate had been omitted. Bacteria were finally suspended in the same medium by repeatedly passing them through a syringe, diluted, and inoculated into a 20 ml flask with LMM or LMM in the presence of Rpf (31 pmol/l). The initial cell density was ca. 102 viable cells per ml and incubation was at 30°C with intensive shaking. Growth was monitored by plating 0.1 ml samples on plates containing nutrient broth E solidified with agar.