TABLE 3.
Growth of D. desulfuricans wild-type strain G20 and cycA mutant I2 on selected substrates
| Growth medium | Level
of growtha
|
|
|---|---|---|
| Wild-type G20 | Mutant I2 | |
| Lactate-sulfate | 1.6 ± 0.3 | 1.6 ± 0.3 |
| Pyruvate-sulfate | 1.5 ± 0.2 | >20 |
| Hydrogen-sulfate | 100% | 89% ± 22% |
a
Doubling times (in hours) were determined by monitoring the absorbance at 600 nm of cultures grown at 37°C on lactate-sulfate (14 determinations) or pyruvate-sulfate (3 determinations in duplicate). Growth on hydrogen-sulfate was evaluated by measuring increases in protein of the cultures incubated with or without hydrogen in the headspace. A value of 100% for the wild type averaged 7.3 μg/ml with four independent determinations performed in duplicate.