Fig. 3

NUR / mmol L⁻¹ h⁻¹ of M. marburgensis with different NH₄⁺ concentrations calculated by the THp_N2fix methodology. Negative values for NUR / mmol L⁻¹ h⁻¹ on the y-axis indicate N₂-fixation. Sample size varies due to the time point of undercutting THp_N2fix. The sample number (n) is indicated in brackets on the x-axis. In addition, the sampling time points (in h) and the values of the applied NH₄⁺ concentration (in %) are also indicated on the x-axis.