Table 2.

Anaerobic SOD activity and corresponding survival after a shift from anaerobiosis to aerobiosis of the E. coli sodA sodB recA straina

PlasmidIPTG (μM)% Aerobic survivalbSOD activity (U/mg of protein)
pRS41.1c 00.005 ± 0.002Not detected
pDT1-191089.4 ± 3.511.0 ± 0.42
pRS51c 107.8 ± 4.151.4 ± 0.33
50077.7 ± 2.04.8 ± 0.65
  • a Cultures were grown overnight anaerobically in the presence of IPTG. SOD activity was determined by the xanthine oxidase/cytochrome c assay, and cells were plated under anaerobic and aerobic conditions with IPTG. Colonies were counted after overnight incubation. Values are means of three independent experiments, and standard errors are indicated.

  • b Ratio of the number of colonies under aerobic and anaerobic conditions.

  • c Small colonies.