TABLE 1.

β-Galactosidase activities from the reductase promoter-lacZ fusions in wt or mutant B. melitensis strains

FusionStrainβ-Galactosidase activitya
PnarK-lacZwt1,091 ± 159
narR457 ± 51
PnirK-lacZwt49 ± 12
nnrA1 ± 0.6
PnorC-lacZwt640 ± 25
nnrA9 ± 5
nnrB698 ± 46
PnosR-lacZwt304 ± 81
nnrA4 ± 2
nnrB395 ± 61
  • a Bacteria were grown microaerobically in rich medium (2YT) supplemented with 10 mM of NaNO3 before β-galactosidase activity was determined. Activity (in Miller units) (8) is the average of three independent clones.