TABLE 3.

Effect of S. gordonii Challis on bacteriocin produced by S. mutans GS5^a

Supplement in THBY	Diameter of inhibition (mm)b
	Without Challis	With Challis
None	0 ± 0	0 ± 0
Glucose	0 ± 0	0 ± 0
Sucrose	24.5 ± 0.5	24.0 ± 1.0
CSP	39.5 ± 0.5	39.5 ± 0.5

^aSupernatant fluids from S. mutans GS5 grown in broth cultures in THBY supplemented with 1% glucose, 1% sucrose, or 0.1 μg of CSP per ml were mixed with S. gordonii Challis (10⁷ CFU) and incubated in precut wells in THB agar plates for 24 h at 37°C. The wells were then filled using THB with 1% low-melting-point agarose, and the plates were overlaid with the indicator strain RP66 (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 inhibition zones surrounding the wells were measured.

^bValues are means ± standard deviations from two experiments.