1. Multi-heme cytochrome-mediated extracellular electron transfer by the anaerobic methanotroph 'Candidatus Methanoperedens nitroreducens'.
- Author
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Zhang X, Joyce GH, Leu AO, Zhao J, Rabiee H, Virdis B, Tyson GW, Yuan Z, McIlroy SJ, and Hu S
- Subjects
- Anaerobiosis, Oxidation-Reduction, Metals, Cytochromes genetics, Methane, Heme, Electrons, Archaea genetics
- Abstract
Anaerobic methanotrophic archaea (ANME) carry out anaerobic oxidation of methane, thus playing a crucial role in the methane cycle. Previous genomic evidence indicates that multi-heme c-type cytochromes (MHCs) may facilitate the extracellular electron transfer (EET) from ANME to different electron sinks. Here, we provide experimental evidence supporting cytochrome-mediated EET for the reduction of metals and electrodes by 'Candidatus Methanoperedens nitroreducens', an ANME acclimated to nitrate reduction. Ferrous iron-targeted fluorescent assays, metatranscriptomics, and single-cell imaging suggest that 'Ca. M. nitroreducens' uses surface-localized redox-active cytochromes for metal reduction. Electrochemical and Raman spectroscopic analyses also support the involvement of c-type cytochrome-mediated EET for electrode reduction. Furthermore, several genes encoding menaquinone cytochrome type-c oxidoreductases and extracellular MHCs are differentially expressed when different electron acceptors are used., (© 2023. Springer Nature Limited.)
- Published
- 2023
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