Table 1

Growth parameters and isotope fractionations in batch cultures containing different concentrations of iron and ammoniuma

Organic substrateConcn of:Growth yield (106 cells/μmol sulfate reduced)csSRR (fmol/cell/day)Sulfide produced (mM)Isotopic ratio (‰):
NH4ClFeCl2 (μM)δ34Ssulfateδ34Ssulfide34ε
Lactate5.6 mM829 ± 528.1 ± 2.67.42.0−6.46.8 ± 0.2
5.6 mM832 ± 525.1 ± 2.58.73.1−5.97.0 ± 0.2
5.6 mM<115 ± 218.7 ± 1.49.35.5−9.911.7 ± 0.3
5.6 mM<118 ± 320.1 ± 1.78.24.8−8.410.4 ± 0.3
112 μM87 ± 162.4 ± 5.28.53.3−7.48.4 ± 0.3
56 μM89 ± 162.9 ± 5.78.63.4−6.77.8 ± 0.2
Malate5.6 mM8114 ± 185.3 ± 0.76.85.5−14.616.7 ± 0.3
5.6 mM894 ± 154.9 ± 0.56.66.6−16.319.1 ± 0.3
5.6 mM899 ± 164.3 ± 0.57.57.2−15.918.6 ± 0.3
5.6 mM2110 ± 174.1 ± 0.46.55.7−15.417.5 ± 0.3
5.6 mM<163 ± 102.9 ± 0.34.65.0−23.425.1 ± 0.3
5.6 mM<166 ± 102.2 ± 0.23.13.4−27.928.9 ± 0.3
56 μM819 ± 36.5 ± 0.76.57.8−18.521.9 ± 0.4
5.6 μM816 ± 38.3 ± 0.76.67.8−19.422.6 ± 0.4
0.5 μM819 ± 38.5 ± 0.76.98.6−19.022.7 ± 0.4
  • a Each row represents a single independent experiment, and errors were propagated from analytic uncertainties of cell density, sulfide, and isotope measurements. Isotopic ratios were reported with respect to the laboratory working reference SF6.