FIG 1.

CF efflux by LcS in a fermented milk product (LcS-milk). LcS cells in LcS-milk stored at 4°C for 2 weeks (within the due date of the product) or for 6 months were stained with cFDA and PI and then were analyzed by FCM. CF-efflux activity and cell membrane integrity were evaluated on a CF versus PI plot. In the presence of saccharide, viable LcS cells were identified in the CF⁻PI⁻ gate, indicating efflux positivity and membrane-integrity positivity. “No wash” indicates no treatment of the LcS-milk before staining. “Wash” indicates wash treatment with DPBS to eliminate saccharides from the LcS-Milk sample. “Wash + Glc” indicates the addition of glucose after wash treatment with DPBS.