As of October 2025 the Geobacter pili-vs-cytochrome nanowire dispute is still unresolved: a cytochrome-camp review calling that identity 'widely accepted' drew a direct point-by-point Commentary rebuttal from Lovley in the same journal

electromicrobiologygeobactermicrobial-nanowirescytochromee-piliscientific-controversy

A 2025 review by Media Zakizadeh Tabari and Allon I. Hochbaum (University of California, Irvine), "Electron transport across the cell envelope via multiheme c-type cytochromes in Geobacter sulfurreducens" (Frontiers in Chemistry, 2025-07-16), states that although the identity of the organism's conductive filaments "was hotly debated, (Bond et al., 2012; Snider et al., 2012; Yates et al., 2016), these are now widely accepted to be networks of MHCs" (multi-heme c-type cytochromes) — the structural view established by the cryo-EM work (claim-geobacter-conductive-filaments-are-omcs-cytochrome-polymers).

Derek R. Lovley, originator of the rival e-pili model (claim-lovley-2005-proposed-geobacter-nanowires-are-conductive-pili), published a formal Commentary responding directly to that review in the same journal three months later (Frontiers in Chemistry, 2025-10-20). It opens: "In their review (Tabari and Hochbaum, 2025), Tabari and Hochbaum selectively cite a few references to make the claim that the predominant electrically conductive filaments emanating from Geobacter sulfurreducens are cytochrome filaments that are required for long-range extracellular electron transfer (EET). This commentary briefly outlines the extensive literature that Tabari and Hochbaum omitted that contradicts their claims." Its stated position remains the e-pili one: "Cytochrome filaments are not essential for Fe(III) oxide reduction. Their role in other forms of EET requires further clarification."

This is a direct, named, peer-reviewed exchange — not a secondary summary of an old dispute — published within the same three-month window, in the same venue, about the same organism. As late as October 2025 the field had not converged: one camp characterizes cytochrome identity as "widely accepted," the other publishes a point-by-point rebuttal in the next issue. No third paper adjudicating between them (authored by neither camp) was surfaced. It is the most recent documented round of a fight tracked across this cluster at claim-malvankar-lab-overturned-pili-model-without-lovley, claim-guberman-pfeffer-blames-measurement-not-cytochrome-identity, and the within-study test at claim-ye-2022-mbio-within-study-test-of-pili-omcs-omcz-finds-division-of-labor.