Fig 5.

Quantification of the mRNA levels of the echE hydrogenase gene by qRT-PCR in the mid-exponential (16 h) and stationary (32 h) phases of both the WT (A) and ΔhynAB mutant (B) strains grown under the following conditions: LS, 40 mM lactate–40 mM sulfate; PS*, 40 mM pyruvate–5 mM sulfate; P, 40 mM pyruvate; HS, 1 atm H₂–20 mM sulfate. Black bars, 16 h; white bars, 32 h. The expression of the echE gene was normalized to that of the 16S rRNA gene. The standard errors of all values are shown.