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説明:

Microbial extracellular electron uptake (EEU) is central to bioelectrochemical processes and biocorrosion, yet its underlying mechanisms are not fully understood under microbially influenced iron corrosion. Here, we investigate how excess Fe2+ modulates EEU in Desulfovibrio ferrophilus IS5, a strain that causes severe anaerobic iron corrosion via outer-membrane cytochromes (OMCs)-mediated electron uptake. We show that IS5 grown with elevated Fe2+ exhibits substantially enhanced EEU. This enhancement arises through two complementary mechanisms: (i) increased abundance of functional OMCs via the upregulation of a cytochrome assembly protein, and (ii) an additional electron transfer route mediated by FeS nanoparticles precipitated on the IS5 outer membrane. This indicates that, during iron corrosion, when IS5 cells are found within thick layers of corrosion products and biofilms, they simultaneously utilize both OMCs and FeS nanoparticles to sustain high-rate EEU from iron under conditions of high Fe2+ concentrations and limited organic substrates. This study advances the mechanistic understanding of EEU-driven iron corrosion and highlights a potential avenue for manipulating bioelectrochemical systems.

権利情報:

• Creative Commons BY-NC-ND Attribution-NonCommercial-NoDerivs 4.0 International
  

キーワード: microbially influenced corrosion, sulfate-reducing bacteria, iron sulfide nanoparticles, outer-membrane cytochrome, electrochemical analyses, transmission electron microscopy, transcriptome

刊行年月日: 2026-04-15

出版者: Iron and Steel Institute of Japan

掲載誌:

• ISIJ INTERNATIONAL (ISSN: 13475460) vol. 66 issue. 5 p. 685-691

研究助成金:

原稿種別: 出版者版 (Version of record)

MDR DOI:

公開URL: https://doi.org/10.2355/isijinternational.isijint-2025-353

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更新時刻: 2026-04-16 15:19:59 +0900

MDRでの公開時刻: 2026-04-16 16:26:09 +0900