Sensitivity of the Δ<i>katA</i> mutant to A-NO₂⁻.

<p><b>A.</b> Wild-type strain <i>P. aeruginosa</i> PAO1, Δ<i>katA</i> mutant, and the complemented mutant Δ<i>katA</i>::<i>katA</i> were cultured aerobically in either LB broth (pH 6.5) or LBN broth (pH 6.5) for 24 hrs (<b>left panel</b>), or anaerobically in either LB broth (pH 6.5) or LBN broth (pH 6.5) for 48 hrs <b>(right panel)</b> supplemented with 0, 15, 20, 25 and 30 mM NaNO₂, respectively. Cells were plated out directly on LB agar medium to determine the sensitivity to A-NO₂⁻. <b>B.</b> Anaerobic cultures in LBN (pH 6.5) without A-NO₂⁻ were serially diluted and spotted on LB agar plates to demonstrate the similar growth occurred in all test strains. <b>C.</b> Wild-type PAO1, Δ<i>katA</i> mutant, and the complemented mutant Δ<i>katA</i>::<i>katA</i> were cultured anaerobically for 72 hrs in LBN broth (pH 6.5) supplemented with 0, 20 mM, and 25 mM NaNO₂, respectively. Culture aliquots were removed daily, and serial cell dilutions were plated out on LB agar medium to enumerate CFU. The experiments were repeated three times and the representative data were shown.