FIG 5.

Diazotrophic growth of Pelobacter strain SFB93 under N₂ (red) versus Ar (blue), with acetylene as the carbon and energy source. (A) Growth measured by optical density (solid lines) and cell counts (dashed lines). (B) Consumption of acetylene, which, after depletion, was added again to the gas phase at four times, as indicated by the arrows. (C) Ethylene accumulation. Symbols represent the means of three separate cultures, and bars indicate ±1 standard deviation.