Growth of MS_Vec and MS_Rv3402c under stress conditions.

<p>(A). Growth of MS-Vec and MS-Rv3402c at 37°C in MB 7H9 liquid medium was monitored by determining OD₆₀₀ at intervals of 3 h. (B). Growth curve of MS-Vec and MS-Rv3402c in iron-depleted medium. Two recombinant <i>M. smegmatis</i> were grown in MB 7H9 medium supplemented with 100 μM 2′ 2′ dipyridyl. The growth of the strains were monitored by measuring OD₆₀₀ at intervals of 6 h. (C). <i>In vitro</i> growth of MS-Vec and MS-Rv3402c at different pH. The bacteria were collected by centrifugation and resuspended to an OD₆₀₀ of 0.5 in 5 ml MB 7H9 (pH 5 or 3). All cultures were again incubated at 37°C and 0.1 ml removed for viable count enumeration after 0, 3 and 6 h. (D). Survival of recombinant <i>M. smegmatis</i> after exposure to hydrogen peroxide. Aliquots (5 ml) of cultures at OD₆₀₀ of 0.5 were exposed to 5 mM hydrogen peroxide (H₂O₂) for 6 h at 37°C. The cultures were serially diluted and plated onto MB 7H10 plates and the colonies counted after 3–4 days of incubation at 37°C.