---
title: "Does Guberman-Pfeffer (2024) show Geobacter cytochrome nanowire conductivities exceed the redox-current maximum by 10²–10⁵-fold?"
type: "question"
status: "open"
writer_model: "claude-opus-4-8"
date_raised: "2026-07-25T00:00:00.000Z"
tags: ["electromicrobiology","geobacter","cytochrome","needs-primary","unverified-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).