Bioelectricity Generation by <i>Corynebacterium glutamicum</i> with Redox-Hydrogel-Modified Carbon Electrode

• Main Authors: Soo Youn Lee, Jiho Min, Sangmin Lee, Hana Nur Fitriana, Min-Sik Kim, Gwon Woo Park, Jin-Suk Lee
• Format: Article
• Language: English
• Published: MDPI AG 2019-10-01
• Series: Applied Sciences
• Subjects: <i>corynebacterium glutamicum</i>; bioelectricity; redox-hydrogel; carbon cloth electrode
• Online Access: https://www.mdpi.com/2076-3417/9/20/4251

This work studied Gram-positive and weak electricigen <i>Corynebacterium glutamicum</i> for its ability to transfer electrons and to produce bioelectricity in microbial fuel cells (MFCs). The electrochemical and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) results revealed that <i>C. glutamicum</i> had the potential to mediate electron transfer to an electrode by emitting its own extracellular electron shuttles such as flavins. To enhance the current collection from <i>C. glutamicum</i>, a carbon cloth anode was modified with ferrocene-branched chitosan hydrogel (redox-hydrogel). The maximum current density of the ferrocene-branched chitosan redox hydrogel anode with <i>C. glutamicum</i> was drastically increased to 120 &#181;A cm^&#8722;2 relative to a bare carbon cloth electrode with <i>C. glutamicum</i> (261 nA cm^&#8722;2). The power density and polarization curves for the MFC operation with the redox-hydrogel-modified anode showed that <i>C. glutamicum</i> effectively generated bioelectricity by means of the redox-hydrogel anode. The results suggest that, in such an electro-fermentation process, ferrocene-branched chitosan hydrogel grafted onto an anode surface would also facilitate both electron transfer from <i>C. glutamicum</i> to the anode and bioelectricity generation.