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Updated: Aug 5, 2026
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Electrochemical Detection of Deuterium Kinetic Isotope Effect on Extracellular Electron Transport in Shewanella oneidensis MR-1
Published on: April 16, 2018
Azurins With Tunable Reduction Potentials as Redox Mediators for Extracellular Electron Transfer
Alexis J Holwerda1, Jing-Xiang Wang2, Yang Gao3
1Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Austin, Texas, USA.
Chembiochem : a European Journal of Chemical Biology
|July 26, 2026
Summary
Researchers used azurin, an electron transfer protein, as a redox mediator to enhance extracellular electron transfer (EET) in electroactive microbes like Shewanella oneidensis MR-1. This protein improves microbial fuel cell performance and biocatalytic reactions.
Area of Science:
- Microbiology
- Biochemistry
- Bioelectrochemistry
Background:
- Electroactive microbes facilitate bioelectrochemical applications.
- Small-molecule redox mediators like flavins have limitations in redox range and synthesis.
- Improving extracellular electron transfer (EET) is key for microbial applications.
Purpose of the Study:
- To investigate azurin as a novel redox mediator for Shewanella oneidensis MR-1.
- To evaluate azurin's effectiveness in enhancing EET for various applications.
- To compare azurin's performance against traditional small-molecule mediators.
Main Methods:
- Studied the reduction of four azurin variants by S. oneidensis MR-1.
- Determined kinetic parameters (K M) for azurin reduction.
- Applied azurin as a mediator in biocatalytic reactions and microbial fuel cells.
Main Results:
- S. oneidensis MR-1 reduced multiple azurin variants over a 440 mV range.
- Azurin reduction rate depended on concentration and redox potential.
- Azurin mediated biocatalytic reactions (e.g., polymerization, dye decolorization) and improved microbial fuel cell current.
Conclusions:
- Azurin serves as an effective redox mediator for S. oneidensis MR-1 EET.
- Engineered redox proteins offer advantages over small molecules for EET applications.
- Azurin shows potential for bioelectrochemical and electrosynthetic applications.
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