We uncover and map unexpected molecular “wiring” that cells and proteins use to shuttle electrons—revealing new avenues for bioenergy and biotechnology.
🔹 Flavin-based extracellular electron transfer in Gram-positives
We discovered that many Gram-positive bacteria naturally secrete flavin molecules (vitamin B₂ derivatives) as soluble electron shuttles. This overturns the assumption that only Gram-negative microbes can export electrons efficiently for processes like mineral reduction or microbial fuel cells.
🔹 Identifying the elusive ACNQ shuttle in Shewanella
Our work revealed and characterised ACNQ—a small, non-enzymatically produced quinone—that Shewanella oneidensis releases to ferry electrons from its metabolism to external acceptors. Although not genetically encoded, ACNQ plays a vital role in extracellular electron transfer.
Why it matters:
🔎 Reveals new mechanisms: Expands the known toolkit of natural electron shuttles beyond traditional pathways.
🔎 Broadens organism scope: Opens opportunities to use Gram-positive microbes in bioelectronic systems.
🔎 Informs system design: Guides synthetic biology and material integration by identifying key electron mediators.