Fig 3.

Gene fitness for diazotrophic growth and growth on various nitrogen sources. (A) Comparison of fitness values between growth with ammonium and N₂ as nitrogen sources versus N₂ only (both in the presence of acetate and H₂). MMP_RS02675 encodes a DUF364. Each value is the average of three replicate experiments. (B) Heatmap showing overview of fitness data for select genes strongly cofit with nifH across conditions with varying nitrogen sources added. N₂ is present in all conditions. (C) Growth of M. maripaludis with various nitrogen sources. Averages and standard deviations are calculated from four replicate cultures. N₂ is absent in all conditions except N₂ fixing (blue circles). (D) Fitness for growth in formate oxidizing conditions with ammonium or adenosine added as a nitrogen source. Values are averages of three experiments. (E) Heatmap showing fitness data for genes of interest for alanine metabolism. N₂ is present in all conditions.