TABLE 3.
Influence of growth conditions on streptococcal metabolism
| Growth condition | Synthesis [nmol/(min · 109
cells)] ofa:
|
|
|---|---|---|
| H2O2 | Lactic acid | |
| Shaken in air | 15.5 ± 1.0 | 17.0 ± 0.6 |
| Static in air | 9.9 ± 0.8 | 30.5 ± 1.8 |
| Shaken −O2b | 5.4 ± 0.4 | 32.6 ± 2.9 |
a
After growth to mid-logarithmic phase under the indicated conditions, initial rates of hydrogen peroxide and lactic acid formation by S. gordonii CH1 were determined with fully aerated assay buffer, as described in Materials and Methods and in the legend to Fig. 1. The glucose concentration for all determinations was 1 mM, and results are means ± SD of three rate determinations under each growth condition.
b
Culture medium was deoxygenated by shaking overnight at 37°C in GasPak anaerobic canisters; the medium was then inoculated with bacteria under a stream of nitrogen gas, and the bacteria were grown in canisters containing fresh H2 and CO2 generator envelopes.