<i>P</i>. <i>aeruginosa</i> and Δ<i>nfuA</i> mutant plating efficiency and growth under aerobic and anaerobic conditions.

<p>The plating efficiency and growth of PAO1 and various mutant strains were determined. Bacteria were grown in LB for aerobic conditions and in LB plus 1% KNO₃ for anaerobic conditions. The plating efficiency was defined as the number of CFU under anaerobic conditions divided by the number of CFU under aerobic conditions. The asterisk indicates statistically significant differences (paired <i>t</i>-test, <i>p</i> < 0.05) compared with the aerobic condition. (A) The plating efficiency and colony morphology of PAO1 and <b>Δ</b><i>nfuA</i> mutant strains under aerobic and anaerobic conditions was determined. The PAO1, <b>Δ</b><i>nfuA</i>::NfuA strains expressing wild-type NfuA or mutated NfuA (NfuA_C152S, NfuA_C155S, and NfuA_C43,47S) were spotted onto plates containing 1% KNO₃ and incubated under aerobic and anaerobic conditions. (B) Plating efficiency of the PAO1 (PAO1::Tn7T), <b>Δ</b><i>nfuA</i> mutant (<b>Δ</b><i>nfuA</i>::Tn7T) and various complemented strains as in (A), with the addition of <b>Δ</b><i>iscR</i>/pIscR and <b>Δ</b><i>iscR</i>::NfuA/pIscR strains performed under aerobic and anaerobic conditions. Growth of <i>P</i>. <i>aeruginosa</i> strains under aerobic (C) and anaerobic (D) conditions in broth supplemented with 1% KNO₃ incubated at 37°C with 180 rpm shaking was determined. The OD_600nm was monitored at hourly intervals for 24 h. Typically representative results of five independent experiments are shown.