Fig. 5: Simultaneous N2O and O2 reduction by Methylocella tundrae T4 cells during CH4 oxidation in microrespirometry (MR) and growth experiments.
From: Nitrous oxide respiration in acidophilic methanotrophs
A MR experiment showing the simultaneous reduction of N2O and O2 by Methylocella tundrae T4 cells during CH4 oxidation. B N2O and O2 reduction rates by cells of strain T4 during CH4 oxidation calculated from (A). The filled orange and blue dots in the upper (A) represent the concentrations of dissolved O2 and N2O, respectively. The filled orange and blue dots in the bottom (B) represent the rates of O2 and N2O reduction, respectively. Experiments were performed in a MR chamber fitted with O2 and N2O microsensors. The red arrow marks the addition of CH4 (~406 µM) into the MR chamber. The black arrow marks the addition of ~26 µM or ~60 µM O2 into the MR chamber. The gray-shaded area represents points where N2O and O2 are reduced simultaneously. C Growth experiment showing Methylocella tundrae T4 cells reducing N2O and O2 simultaneously during CH4 oxidation. The culture was grown in 2-liter sealed bottles (triplicates) containing 60 mL of LSM medium with 2 mM NH4+ as the N-source. The headspace of the bottles was composed of CH4 (5%, v/v), O2 (0.5%, v/v), N2O (1.4%, v/v), and CO2 (5%, v/v) and supplemented with additional O2 (~0.5%, v/v) before its depletion. The incubation period shown in (C) is after the initial 20-day incubation period. After the depletion of O2, additional O2 was spiked to observe the simultaneous reduction of O2 and N2O during CH4 oxidation. Data are presented as the mean ± 1 SD of a triplicate experiment, and the error bars are hidden when they are smaller than the width of the symbols. Source data are provided as Source Data file.
