Killing activity of CFCSs of the probiotic Lactobacillus strains L. johnsonii La1, L. rhamnosus GG, L. casei Shirota YIT9029 (LcS YT9029), L. casei DN-114 001, L. rhamnosus GR1, and L. sakei CWBI 030202. (A) Killing activity of CFCSs in the presence of DMEM. (B) Effect of MRS-HCl, MRS-LA, and L. johnsonii La1 CFCS on the viability of Salmonella enterica serovar Typhimurium strain SL 1344 at the stationary or exponential growth phase. The killing effect was measured in the presence of DMEM. Values significantly different from control values are indicated by an asterisk (P < 0.01).