Fig. 2

Impact of prior adaptation to acetic acid on growth in acetic acid-containing media. In all experiments, adapted precultures of S. cerevisiae CEN.PK113-7D were grown on SMG (pH 4.5) with 9 g/L acetic acid while non-adapted precultures were grown on SMG set at pH 6.0. a OD₆₆₀ after 5 days of incubation in 96-well plates containing SMG supplemented with 0–15 g/L acetic acid and inoculated with adapted or non-adapted precultures. Data represent average and standard deviation of 32 replicate wells distributed over two independent experiments for adapted CEN.PK113-7D cells (shown in grey) and from 144 replicates from six independent experiments for non-adapted CEN.PK113-7D cells (shown in black) per acetic acid concentration. The average final OD₆₆₀ was based on only wells in which growth occurred (final OD₆₆₀ >0.075), except for non-adapted cells incubated with 11–15 g/L, for which the average OD₆₆₀ of all replicates is shown (fewer than 5.7 % of wells were rejected based on this criterion). b Specific growth rate of CEN.PK113-7D in the same experiment. Data represent the average values and standard deviations calculated from three to six replicates distributed over four independent experiments for adapted CEN.PK113-7D cells (shown in grey) and five to ten replicates distributed over five independent experiments for non-adapted CEN.PK113-7D cells (shown in black). c OD₆₆₀-based growth profiles in SMG with 9 g/L acetic acid, inoculated with acetic-adapted (grey) and non-adapted (black) precultures. d Fraction of stationary phase population capable of colony formation on SMG agar (pH 4.5) containing 9 g/L acetic acid during a serial transfer experiment in shake-flasks. The first flask was grown on SMG (pH 6.0) without acetic acid (referred to as #1 AA−), followed by a culture grown on SMG (pH 4.5) with 9 g/L acetic acid (referred to as #2 AA+). The three subsequent, consecutive cultures were grown on SMG (pH 6.0) without acetic acid (referred to as #3 AA−, #4 AA− and #5 AA−)