Table 2.

Effect of different stresses on the regulation ofkatC expression determined by measuring β-galactosidase activity

Stressoraβ-Galactosidase activityb
None10,309 ± 1,087
Heat (37°C)41,253 ± 1,233
Salt (4% NaCl)33,485 ± 941
Ethanol (4%)27,189 ± 1,562
H2O2
 1 mM10,112 ± 620
 100 μM9,116 ± 943
 10 μM8,960 ± 1,021
Paraquat (10−3 M)29,777 ± 779
  • a S. meliloti RKCZ01 bacteria were grown for 36 h in M9 medium and subjected to indicated stressor for 1 h.

  • b Values were obtained by using duplicate samples from two independent experiments and are given as Miller units per milligram of protein ± the standard errors of the means.