Fig. 3: Anaerobic growth of Methylocella strains on methanol or pyruvate as the sole electron donor and NO₃⁻ as the terminal electron acceptor.

Methylocella tundrae T4 and Methylocella silvestris BL2 cells were grown in LSM medium supplemented with 30 mM methanol and 2–4 mM NO₃⁻. NH₄⁺ (2 mM) was supplied as the N-source. Anaerobic growth of Methylocella tundrae T4 (A) and Methylocella silvestris BL2 (B) cells on methanol as the sole electron donor with NO₃⁻ as the sole electron acceptor. Anaerobic growth of Methylocella tundrae T4 (C) and Methylocella silvestris BL2 (D) cells on pyruvate as the sole electron donor with NO₃⁻ as the sole electron acceptor. N₂O produced from NO₃⁻ reduction by cells of Methylocella silvestris BL2 grown on methanol or pyruvate is shown as an inset plot within each figure. N₂O production was not observed in strain T4, hence inset plots for N₂O production were not displayed. Lower NO₃⁻ (ca. 2.0 mM) was used in the case of methanol (A) to avoid NO₂⁻ toxicity. Growth was determined by optical density measurements at 600 nm, followed by measurements of NO₃^- and NO₂⁻ concentrations. Data are presented as mean ± 1 SD of triplicate experiments, and the error bars are hidden when they are smaller than the width of the symbols. Source data are provided as Source Data file.