Fig. 2.
Survival of the L. lactis cremoris strains during acid challenge (pH 3.0) as a function of the growth conditions. L. lactis cremoris wild type, open bars; L. lactis cremoris Δcfa strain, gray bars; L. lactis cremoris Δcfa + pDLcfa, black bars. Cells were grown until stationary phase, harvested, and resuspended in M17/3. Viability cells were counted after 3 h of acid shock. The strain survival was defined as the ratio of colonies (number of CFU) formed on M17/7 agar medium at the sampling time versus T0. Each value is the mean from three determinations. The summed data presented are the mean values ± standard deviations of replicate values. An asterisk means that there is no significant difference between these values. A value of 1 for the relative survival corresponds to 3.108 cells/ml.