Fig 3. Inducer dependency for the growth of M. tuberculosis and M. smegmatis LeuRS conditional expression strains.
Several confirmed recombinant colonies were grown in the presence of inducer till they reached mid-log phase, cells were washed, resuspended in fresh 7H9 broth and the cultures were either spotted or various dilutions plated for enumerating colony forming units (CFUs). Plates were incubated at 37°C for 28 days for M. tuberculosis strains and 48 hours for M. smegmatis strains, respectively. (A). Recombinant colonies (1 and 2) of TleuS/KD-P analysed for growth in the absence (left) and the presence (right) of P1; N, -1 and -2 are the undiluted, 10−1 and 10−2 dilutions. (B). Culture dilutions of SleuS/KD-P and SleuS/KD-I strains were plated with and without P1 and IPTG, respectively. Bars in the graph represent CFU/ml calculated from the colony numbers that appeared on plates under each of the growth condition specified.