TABLE 5.
Comparison of bacteriocin production by mixed cultures of S. mutans BM71 S. gordonii Challis in broth or biofilmsa
| Supernatant from strain(s) | % Killing of indicator RP66b
|
|
|---|---|---|
| Broth | Biofilms | |
| BM71 alone | 98.3 ± 0.3 | 99.6 ± 0.4 |
| BM71 + Challis | 0 ± 0 (537/406) | 0 ± 0 (517/353) |
| BM71 + BYW1 | 97.1 ± 1.0 (447/356) | 52.9 ± 7.0 (479/146) |
a
A 100 μl aliquot from S. mutans BM71 alone or in a mixture with S. gordonii Challis from a broth or biofilm culture was mixed with 5 × 104 CFU of RP666 indicator cells (in 100 μl of THB) and incubated at 37°C for 1 h. Two micro liters of the culture was plated on the surface of a TSA plate and incubated for another 24 h at 37°C under anaerobic conditions.
b
Values are means ± standard deviations from two experiments. The values in parentheses are the total number of S. mutans cells (106)/total number of S. gordonii cells (106) counted on mitis salivarius plates.