TABLE 1

GTP/ATP ratios in B. subtilis upon antibiotic treatmenta

ConditionMean GTP/ATP ratioSDSEM
No treatment0.540.240.03
Mup70 nM0.180.040.05
Mup70 nM Thio100 nM1.120.720.24
Mup70 nM Tet100 μM1.510.660.13
Mup70 nM Cam100 μM0.550.350.12
Mup70 nM Trim100 μM0.210.060.01
  • a Artificial starvation for isoleucine induced by addition of 70 nM mupirocin was countered by the secondary antibiotic challenge. At 30 min after the addition of antibiotics, samples were collected, and the nucleotide levels were determined by HPLC. Experiments were performed with BSB1 B. subtilis wild-type strain grown at 37°C in MOPS medium supplemented with 0.4% glucose and a full set of 20 amino acids at 25 μg/ml. Mup, mupirocin; Thio, thiostrepton; Tet, tetracycline; Cam, chloramphenicol; Trim, trimethoprim.