Bacteria were enumerated in triplicate after storage of the fermented
skim milk at 4 C either for 1 day (D1) or for 7 days (D7).
Aliquots (1.0 mL) of each sample were diluted with 9 mL of 1 g/L
sterile peptonated water. After serial dilutions, bacteria were
counted by the pour plate technique. St colonies in co-cultures
were counted in M17 agar after aerobic incubation at 37 C for
48 h. Lb, La and Lr were enumerated in MRS agar, after pH adjustment