Figure 5. Conditional essentiality of korAB for growth of M. tuberculosis.

(A) Serial dilutions of single cell suspensions of M. tuberculosis mc²7000 (wild type) and the ΔkorAB strain were spotted on supplemented 7H10 medium containing glycerol (0.5%), dextrose (0.2%) and Tween 80 (0.05%) with or without 200 µM 3NP. Plates were incubated under atmospheres with indicated amounts of CO₂ for 20 days. (B) Growth of M. tuberculosis mc²7000 (squares), ΔkorAB (circles) and complemented strain (diamonds) in supplemented 7H9 medium with glycerol and dextrose without oleic acid or Tween 80 under an atmosphere containing 0.04% CO₂. (C–E) Growth of M. tuberculosis mc²7000 (squares), ΔkorAB (circles; filled circles, 0.1% succinate) and complemented strain (diamonds) in supplemented 7H9 medium with Tween 80 (0.5%) as the sole carbon source under atmospheres containing 5% (C), 0.08% (D), and 0.04% CO₂ (E).