Fig. 2.

Growth characteristics and lipid composition of the accD6 conditional mutant D6DCO2 incubated at 30 and 42 °C. (a) Growth curves of strains mc²155/pCG76 (●, ○) and D6DCO2 (▼, △) incubated at 30 °C (black symbols) and 42 °C (white symbols). Saturated cultures grown at 30 °C were diluted in fresh 7H9 medium supplemented with ADS to an OD₆₀₀ of 0.1 and further incubated at 30 or 42 °C. The arrow indicates growth arrest of D6DCO2. (b) At different time points, the number of viable cells of D6DCO2 in the cultures grown at 30 °C (●) and 42 °C (○) was evaluated by plating serial dilutions onto LB plates at 30 °C. (c) Saturated cultures of strains mc²155/pCG76 and D6DCO2 were diluted in fresh 7H9 medium and incubated at 42 °C. At −3, 1, 2 and 4 h before or after D6DCO2 stopped growing (see a), aliquots from both cultures containing the same number of cells were labelled with [¹⁴C]acetate for 1 h at 42 °C. One half of each sample was used to study the fatty acid and mycolic acid compositions of the strains by TLC (solvent system: hexane/ethyl acetate, 10:1).