Regulatory locus soxRS partially protects Escherichia coli against ozone

FEMS Microbiol Lett. 2001 Feb 20;195(2):175-7. doi: 10.1111/j.1574-6968.2001.tb10517.x.


Ozone is one of the major city air pollutants. Since it is known to induce the overexpression of superoxide-dismutase in various models, and is also a powerful oxidant, we tested if ozone can induce the expression of the soxRS regulon of Escherichia coli, which is activated by superoxide and nitric oxide. A sub-lethal exposure to ozone was unable to activate the expression of soxS'::lacZ transcriptional fusions. However, cells lacking the soxRS locus were more susceptible than wild-type to ozone-mediated killing. Constitutive expression of the soxRS regulon did not increase the resistance to ozone. Ozone might be exerting a selective pressure upon oxidative-stress defense mechanisms in airborne bacteria.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Enzyme Induction
  • Escherichia coli / drug effects
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins*
  • Gene Expression Regulation, Bacterial
  • Isopropyl Thiogalactoside / pharmacology
  • Ozone / pharmacology*
  • Plasmids
  • Recombinant Fusion Proteins / metabolism
  • Regulon*
  • Superoxide Dismutase / biosynthesis
  • Trans-Activators*
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism


  • Bacterial Proteins
  • Escherichia coli Proteins
  • Recombinant Fusion Proteins
  • Trans-Activators
  • Transcription Factors
  • SoxR protein, Bacteria
  • SoxS protein, E coli
  • Isopropyl Thiogalactoside
  • Ozone
  • Superoxide Dismutase