TABLE 2.
Effect of nutritional supplements on growth of the mutS recD strain in minimal medium
| Supplement(s)a | Difference in lag time (h)b | % Reduction in lag timec |
|---|---|---|
| None | 27.8 | |
| Guanine | 0.1 | 99 |
| Adenosine | 1.6 | 85 |
| Guanine + adenosine | −1.4 | 119 |
One microliter of each supplement was added per 200 μl of minimal medium in a microtiter dish. The stock concentration of supplements used was described previously (13).
The difference in lag time equals the time required for the mutS recD strain to resume growth after subculturing minus the time required for the wild-type strain to resume growth under the same conditions.
Percent reduction in lag time is the relative decrease in lag time upon subculturing of the mutS recD mutants into minimal medium with the nutritional supplement indicated. One hundred percent reduction in lag time indicates that the supplement completely eliminated the disproportionate growth lag observed upon subculturing of the mutS recD strain from rich to minimal medium.