Fig. 7.

Requirement for reduced F₄₂₀ for NO₂ detoxification in M. smegmatis. The sensitivities of wild-type, fgd::aph, Δfbic::aph, fgd::aph (pEP-fgd), and Δfbic::aph (pEP-fbiC) strains to NO₂ were studied. In each case, the cells were exposed to NO₂ by incubating a corresponding diluted suspension in growth medium with spermine-NONOate under air; a control culture received water in place of spermine-NONOate solution. In each case, including for the control, the number of surviving cells per milliliter in a culture is presented as a percentage of the value recorded for a sample drawn before incubation with spermine-NONOate (or water); as a result, the value even for the control culture was <100%. Each error bar was calculated from measurements in triplicate. Gray bar, control culture; black bar, NO₂-exposed culture.