TABLE 1.

Production of bacteriocin by S. mutans GS5 or BM71 in agar plate assaysa

BacteriumDiameter of inhibition zone (mm)b
Without CSPWith CSP
GS5BM71GS5BM71
Wild-type38.3 ± 1.739.0 ± 0.839.0 ± 2.439.3 ± 1.2
comC mutant3.7 ± 2.91.7 ± 1.238.7 ± 2.139.0 ± 0.8
comD mutant2.7 ± 2.11.3 ± 0.52.3 ± 1.71.7 ± 0.5
comE mutant2.3 ± 1.71.7 ± 0.53.0 ± 2.22.3 ± 0.5
  • a S. mutans GS5 or BM71 or their com mutant cells were inoculated into THB agar plates with or without the addition of exogenous synthetic CSP (3 μg in 3 μl) for stab cultures. After 24 h of incubation at 37°C under anaerobic conditions, the plates were overlaid with indicator RP66 cells (106 CFU) in 3 ml of THB with 1% low-melting-point agarose. After 24 more hours of incubation at 37°C under anaerobic conditions, the diameters of the clearance zones surrounding the inoculated bacteria were measured.

  • b Values are means ± standard deviations from three experiments.