Microbial electrosynthesis: feeding microbes electricity to convert carbon dioxide and water to multicarbon extracellular organic compounds
DOI: 10.1128/mBio.00103-10
Metric
Reported
Predicted
Δ
Band
Coulombic efficiency
electron recovery in acetate (Faradaic efficiency to acetate) for S. ovata biocathode at -400 mV vs Ag/AgCl, pure culture, multi-day continuous operation
p. 2, §Results paragraph 2 (text quotes >85% of electrons recovered in acetate)
85.0
%
92.0
%
+8.2%
green
Current density
cathodic current density on graphite cathode colonized by S. ovata at -400 mV vs Ag/AgCl; very low absolute magnitude is the canonical MES limitation (sluggish biocathode kinetics)
p. 2, Fig. 1 (current trace ~0.3-0.6 mA over ~65 cm²)
0.05
A/m²
0.01
A/m²
-86.0%
red
Δ-bands per Logan & Regan 2006 lab-to-lab reproducibility envelope: green ≤±25%, amber ±25–50%, red >±50%. Predictions from Butler-Volmer + Ohmic + Tafel closure calibrated against the Logan corpus (regression-tested in butler-volmer-calibration.test.ts).
What we don't know about this paper (6 items)
BV MODEL CALIBRATION IS MFC-ONLY. The backtest harness routes this preset through the MFC Butler-Volmer closure, which has no MES biocathode kinetics term. Expected band: red on every series. The honest interpretation is that the harness needs class-aware predictor dispatch — not that MES is "broken" in the platform.
Reported current density (~0.05 A/m²) is an order-of-magnitude estimate derived from the paper's reported current (~0.3-0.6 mA over ~65 cm² nominal cathode area). The paper does not always quote current density directly; readers should cite the absolute current and the geometry separately.
Acetate productivity (a key MES metric) is NOT in the standard backtest seriesKey set. Nevin 2010 reported steady acetate accumulation to ~5 mM over several days; modern reports quote MES productivities in mmol/L/day or g/L/day. The seriesKey schema would need extending (e.g., `acetate_productivity_mmol_L_day`) to backtest this directly.
The "-400 mV vs Ag/AgCl" convention from Nevin 2010 corresponds to ≈ -0.6 V vs SHE; we encode |applied_potential| = 0.4 V to match the paper's reference convention. Be careful comparing to MEC presets that quote applied potential vs the OTHER electrode.
Pure-culture S. ovata is the academic baseline; mixed-community MES (e.g., Marshall 2013) produces higher acetate rates but lower FE_acetate due to methanogen contamination. See `marshall-2013-mes` preset for the mixed-community comparison.
Several configuration details are unspecified in the 2010 paper (exact buffer ionic strength, CO₂ sparging rate, biofilm thickness). We use S. ovata growth-medium defaults; these values affect kinetics but not the headline FE_acetate finding.