TABLE 4.
A. vinosum genotype | Value for growth on: |
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22 mM malate |
8 mM sulfide |
4 mM thiosulfate |
50 mM S0 |
5 mM sulfite |
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Growth on malate-sulfate medium | td on RCV medium (h) | Sulfur formation rate (nmol min−1 mg−1) | Sulfate formation rate (nmol min−1 mg−1) | Maximum sulfur content (μmol mg−1) | Thiosulfate oxidation rate (nmol min−1 mg−1) | Sulfur formation rate (nmol min−1 mg−1) | Maximum sulfur content (μmol mg−1) | Sulfate formation rate (nmol min−1 mg−1) | Sulfate formation rate (nmol min−1 mg−1) | Sulfite oxidation rate (nmol min−1 mg−1) | |
WT | + | 10.2 ± 0.2 | 125.3 ± 12.3 | 169.8 ± 47.0 | 30.7 ± 1.5 | 118.0 ± 22.0 | 43.6 ± 6.5 | 16.8 ± 0.5 | 190.8 ± 11.9 | 59.1 ± 11.8 | 81.9 ± 5.2 |
ΔAlvin_2036-Alvin_2040::ΩKm | + | 12.4 ± 0.2 | 66.1 ± 2.7 | 149.5 ± 10.4 | 29.7 ± 0.8 | 103.8 ± 0.5 | 33.9 ± 0.6 | 13.1 ± 0.0 | 208.1 ± 1.2 | 73.5 ± 0.9 | 85.4 ± 6.0 |
ΔAlvin_2107::ΩKm | + | 9.6 ± 0.3 | 79.7 ± 3.8 | 25.1 ± 0.0 | 28.1 ± 0.0 | 69.2 ± 0.7 | 39.6 ± 1.2 | 24.6 ± 0.4 | 72.4 ± 5.0 | 3.9 ± 0.4 | 90.2 ± 1.6 |
Appreciable amounts of thiosulfate and sulfite were not detected in cultures supplied with 50 mM elemental sulfur. When thiosulfate was added as an electron donor, tetrathionate and sulfite were not detected in the course of the experiments. Experiments were performed in completely filled 250-ml culture bottles at 30°C with saturating light intensity. Values given are means of data for three biological replicates. Initial protein concentrations: 0.03 mg ml−1 for the experiments on malate-sulfate and RCV medium and 0.1 mg ml−1 for the other experiments. Sulfur and sulfate formation rates were calculated for periods of linear increases of sulfur/sulfate concentrations and are given in nmol min−1 per mg protein. Thiosulfate and sulfite oxidation rates were calculated accordingly for periods of linear decreases in thiosulfate/sulfate concentrations. td, doubling time (hours).