TABLE 2.

Activity of the ytfE promoter activity under different growth conditions

Supplementa (concn [mM])Mean β-galactosidase activityb ± SD
AerobicAnaerobic
None27 ± 1.234 ± 2.5
Aqueous NO (0.02)NDc551 ± 50
GSNO (0.1)133 ± 18468 ± 138
Spermine NONOate (0.05)943 ± 53575 ± 172
Nitrate (50)40 ± 1.2458 ± 86
Nitrite (5)166 ± 8.71,202 ± 195
  • a Cultures were grown aerobically and anaerobically in minimal medium with glucose as the carbon and energy source. Culture media were supplemented as indicated; nitrate was present throughout growth, and all other supplements were added to growing cultures 90 to 120 min prior to sampling for β-galactosidase assays.

  • b For each condition, β-galactosidase activity was assayed in duplicate in at least three independently grown cultures. Units of activity are as defined by Miller (26).

  • c ND, not done.