FIG. 2.

Growth kinetics of MYC1552, MYC1551, MYC1551(pMJ111), and their wild-type counterparts grown in 7H9 medium in the absence or presence of the purine precursor hypoxanthine. The different strains were grown in 7H9 medium (supplemented with hypoxanthine for MYC1551 and MYC1552) to an optical density at 600 nm (OD₆₀₀) of close to 1. These cultures were diluted in fresh medium in the absence or presence of hypoxanthine (Hx) to reach an OD₆₀₀ of 0.01 and then incubated at 37°C with 5% CO₂. Growth of the strains was monitored by measuring the OD₆₀₀ of the cultures every day.