TABLE 6.
Nitrous acid-induced mutagenesisa
| Treatment | Strain | Surviving fraction | Mutants (CFU/ml)c
|
||
|---|---|---|---|---|---|
| AUr | Valr | Strr | |||
| Bufferb alone | KL16 (nfi+) | 1.0 | 5.8 (± 1.2) × 103 | 2.0 (± 0.4) × 101 | 5.3 (± 5.0) × 100 |
| BW1185 (nfi-1) | 1.0 | 6.9 (± 1.5) × 103 | 5.9 (± 2.9) × 101 | 3.2 (± 1.0) × 100 | |
| Buffer + HNO2 | KL16 (nfi+) | 5.5 (± 1.9) × 10−4 | 4.6 (± 2.1) × 105 | 9.6 (± 3.3) × 104 | 9.8 (± 20) × 101d |
| BW1185 (nfi-1) | 3.8 (± 0.4) × 10−3 | 1.3 (± 0.1) × 106 | 1.7 (± 0.7) × 105 | 1.2 (± 0.2) × 103 | |
a
Means (± standard deviations). With one exception (see footnote d), three culture samples were subjected to each treatment. The standard deviations are presented only to indicate experimental variation and do not imply that the data are normally distributed.
b
Buffer, 0.1 M sodium acetate buffer, pH 4.6.
c
The concentrations of mutants were determined after outgrowth of the cultures to saturation (3 × 109 cells/ml).
d
Six culture samples were tested. The individual results ranged from 0 to 494 Strr mutants per ml, with a median value of 6.