FIG. 3.

Time course of oxidation of H₂ (A to F) and thiosulfate (G to L) and reduction of various electron acceptors such as O₂ (5%, vol/vol) (A, G), nitrate (10 mM) (B, H), ferrihydrite (10 mM) (C, I), selenate (2 mM) (D, J), selenite (2 mM) (E, K), or arsenate (2 mM) (F, L) and concomitant bacterial growth of strain HGM-K1. The bars indicate the 95% confidence intervals (n = 4). Either H₂ (H₂-CO₂, 80:20; 300 kPa) or thiosulfate (10 mM) was provided as an electron donor. The oxidation of thiosulfate to sulfate is indicated only in panel G, while it was observed during bacterial growth with any electron acceptor. Although the oxidation of H₂ was not quantified, the concentration of H₂ in the gas phase was decreased during growth (data not shown).