TABLE 3.
Mutant accumulation in wild-type strain CHA0 cultures after 12 days of incubation in NBY broth containing copper or dilute NBY brotha
| Medium | Total bacterial concn (log10 CFU/ml) | % of orange mutants |
|---|---|---|
| NBY broth | 9.16 | 1.19 |
| NBY broth containing 0.7 mM CuSO4 | 9.05 | 0.52 |
| Dilute (0.1×) NBY broth | 8.99 | 0.02 |
| Dilute (0.1×) NBY broth containing 30 mM NaCl | 8.92 | 0.25 |
a
Broth media were inoculated with overnight CHA0 cultures that contained no detectable mutants. The total numbers of viable bacteria and the percentages of orange-colony mutants were determined after 12 days. The values are means based on 40 replicate cultures from four trials (no significant treatment-trial interaction). Each main effect was significant (P ≤ 0.0001). The means were compared by using Fisher's protected LSD test. The Fisher's LSD0.05 values for total bacterial concentration and percentage of orange mutants were 0.04 and 0.45, respectively.