After the inoculum was added and
allowed to absorb, and 6 mm sterile paper filter discs (Whatmann
n1) moistened with 20 ml of cell free supernatant obtained by
centrifugation (2500 g/10 min) from each isolate of LAB in
exponential growth phase were added. The susceptibility of pathogens
to the discs was assessed by measuring the zone of inhibition
of bacterial growth around the discs (radius e mm) after incubation
for 24 h at 37 C. A clear zone of inhibition of at least 2 mm radius
was recorded as positive. The experiment was performed in
triplicate.