A methane-producing microbe uses discarded strands of RNA as electrical power cables to suck energy out of solid minerals.
RNA is widely known for carrying genetic instructions or building proteins. A microbe named M. barkeri actually secretes RNA into its environment to serve as a conductive wire. These extracellular strands allow the organism to pull electrons from distant surfaces to fuel its metabolism. This is the first time a genetic molecule has been seen acting as a piece of electrical hardware. This discovery could lead to new ways of using microbes to generate clean energy or scrub greenhouse gases from the atmosphere.
Extracellular RNA drives Electromethanogenesis in a Methanogenic Archaeon
bioRxiv · 2025.07.06.663362
Methanogenic archaea account for two-thirds of global methane emissions. Some species, including Methanosarcina barkeri, reduce CO2 by directly acquiring electrons from solid substrates. However, the mechanism of electron acquisition in M. barkeri has remained unclear because this archaeon lacks the multiheme c-type cytochromes that drive extracellular electron transfer in many other microbes. Here we show that M. barkeri releases abundant extracellular nucleic acids during early growth, primari