Does Guberman-Pfeffer (2024) show Geobacter cytochrome nanowire conductivities exceed the redox-current maximum by 10²–10⁵-fold?

electromicrobiologygeobactercytochromeneeds-primaryunverified-quant

The question

claim-2024-paper-disputes-geobacter-cytochrome-nanowire-conductivity rests on a specific magnitude: that the measured conductivities of Geobacter OmcS/OmcZ cytochrome nanowires are "10²–10⁵-fold larger than the computed and biologically reasonable maximum redox current." Does the primary paper actually state this figure, and in what terms?

Why it matters

This is the load-bearing number behind the claim that the Geobacter nanowire dispute is not fully settled — the fourth position in a multi-party controversy (see claim-malvankar-lab-overturned-pili-model-without-lovley). If the magnitude is real and stands, the cytochrome-nanowire model has an unresolved physics problem even though its structure is well resolved (claim-geobacter-conductive-filaments-are-omcs-cytochrome-polymers). The number therefore decides whether the vault should present the cytochrome model as "leading and essentially settled" or "leading but electrically contested."

Why it is a question and not yet verified

The figure was recorded in the capture's "Further leads" section as an inline quote, without the exact-quote source table the capture's four main claims carry, and was not re-fetched in the promotion run. The source venue (Frontiers in Microbiology, peer-reviewed) clears the Tier 1–2 floor for a quantitative claim, but the specific number has not been confirmed against the paper's own text this session.

What would answer it

• Fetch the primary — Guberman-Pfeffer, "To be or not to be a cytochrome...," Frontiers in Microbiology (2024), DOI 10.3389/fmicb.2024.1397124, at https://pmc.ncbi.nlm.nih.gov/articles/PMC11021709 — and confirm the "10²–10⁵-fold" magnitude and exactly what quantities it compares (measured conductivity vs. computed maximum redox current).
• Optionally, check whether any later paper (Malvankar-lineage or third-party) rebuts or concedes the redox-current-ceiling argument, which would move the parent claim toward "settled" or "still open."

Routed from the promotion of 10-inbox/raw/2026-07-16-are-geobacters-conductive-nanowires-protein-pili-or-stacked (2026-07-25).

Progress log

• 2026-08-07 — Answered. The '10²–10⁵-fold' magnitude is confirmed against the primary: verbatim-verified in a 2026-07-26 opus audit of claim-2024-paper-disputes-geobacter-cytochrome-nanowire-conductivity (which resolved that note's [unverified-quant] flag), and independently re-confirmed at the 2026-08-07 capture against a freshly-archived primary (source_sha 3a3a978b85…). The compared quantities are now captured: measured currents versus a computed maximum redox current of 0.14 pA/filament, itself a Marcus-theory result rather than a separate measurement (claim-guberman-pfeffer-0-14-pa-ceiling-is-computed-not-measured). The paper attributes the mismatch to abiological measurement conditions, not to the cytochrome identity being wrong (claim-guberman-pfeffer-blames-measurement-not-cytochrome-identity). The optional second leg — whether a later paper rebuts or concedes the redox-current-ceiling argument — is left as future reading, not a blocker; it does not keep this specific verification open.