Table 1.
Culture | Nitrogen source | Growth rate (h−1) | Doubling time (h) | Yield (g DW/mol CH4) | Limitation | O2 concentrationb (%) |
---|---|---|---|---|---|---|
Batch | Ammoniuma | μmax = 0.07 | 10 | 6.5 | No | 18 |
Nitrate | μmax = 0.04 | 17 | n.d. | No | 18 | |
N2 | μmax = 0.025 | 27 | n.d. | Nitrogen | <1 | |
Chemostat | N2a | μ = 0.017 | 40 | 3.5 | Methane | 0.5 |
Ammoniuma | μ = 0.017 | 40 | 4.9c | Oxygen | <0.03 |
aCells used for transcriptome analysis. In all other Tables referred to as “Cells at μmax,” “N2 fixation,” and “O2 limitation.”
bFor batch cultures initial headspace oxygen concentrations are given, while for the chemostat cultures measured dissolved oxygen concentration (dO2) is expressed as % oxygen saturation (100% equals 800 μmol/l at 55°C).
cCalculated from OD600 comparisons at steady state.