Redox-active molecules in bacterial cultivation media produce photocurrent

• Published in: Biosensors and bioelectronics. X Vol. 21; p. 100558
• Main Authors: Smith, Matthew C., Nasseri, Nathan S., Morin, Emile J., Limwongyut, Jakkarin, Moreland, Alex S., Shlosberg, Yaniv, Carlini, Andrea S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2024; Elsevier
• Subjects: Benzoquinone; Bioelectricity; Cultivation media; Electrical current; Electrochemistry; Flavins; Fluorescence; Fuel cells; NADH; Photocurrent; Yeast extract; NADH; Photocurrent; Yeast extract; LB; Fuel cells; Bioelectricity; Electrochemistry; Fluorescence; Cultivation media; Benzoquinone; Electrical current; Flavins
• ISSN: 2590-1370; 2590-1370
• DOI: 10.1016/j.biosx.2024.100558

Renewable energy concepts such as microbial fuel cells (MFCs) present a promising, yet intrinsically complex electrochemical approach for utilizing bacteria as an electron source. In this work, we show that just the cultivation media for bacterial growth, which is based on yeast extract, is sufficient for generating electrical current in a bio-electrochemical cell (BEC). We apply cyclic voltammetry and 2-dimensional fluorescence spectroscopy to identify redox active molecules such as NADH, NAD+, and flavines that may play key roles in electron donation. Finally, we show that upon illumination, current production is enhanced 2-fold. This photocurrent is generated by a variety of metabolites capable of photochemical reduction, enabling them to donate electrons at the anode of the BEC. [Display omitted] •LB media alone (cell-free) generates electrical current in bio-electrochemical cells (BEC).•White light illumination enhances current production in LB media, yielding photocurrent.•Redox-active molecules (NADH, flavins, quinones) in LB exhibit varied electron donation dependencies under illumination.