The inoculum of LAB was prepared as described above in Section 2.3. Instead of sterile quarter strength Ringer's solution (Lab M), cells were re-suspended in the same volume of BPW adjusted to each sub-lethal condition to be investigated. Cells were exposed to these conditions during 1 h and the samples were taken at time 0 (time of inoculation) and after 60 min. After the exposure to each sub-lethal condition, each suspension was harvested by centrifugation and the cells re-suspended in the same volume of the final solution prepared in 2.4.1.
Cells obtained from the inoculum prepared as described in 2.2 were directly re-suspended in the same volume of the final solution prepared in 2.4.1 and used as a control.
Each experiment was repeated three times.