1. Underground Life Powered by Electrons

    Scanning electron microscopy showing attachment of Delftia sp. WE1-13 on carbon cloth fibers, and in vivo fluorescent image of Delftia sp. WE1-13 cells attached to an electrode during electrochemical analysis. Image source: Y. Jangir and M.Y. El-Naggar (USC). Image credit: None
    Scanning electron microscopy showing attachment of Delftia sp. WE1-13 on carbon cloth fibers, and in vivo fluorescent image of Delftia sp. WE1-13 cells attached to an electrode during electrochemical analysis. Image source: Y. Jangir and M.Y. El-Naggar (USC).

    Scientists from the University of Southern California Life Underground team are taking a close look at microorganisms that have developed unique strategies for surviving below the Earth’s surface in oxygen-poor but mineral-rich environments.

    In the research paper “Isolation and characterization of electrochemically active subsurface Delftia and Azonexus species,” published in Frontiers of Microbiology, the scientists analyze microbes within a fractured-rock aquifer in Death Valley, CA, using electrodes to draw out and isolate types that gain energy through a process called extracellular electron transfer (EET).

    The study is part of growing research on microorganisms able to “live off of electricity.” A recent article from Quanta Magazine followed USC biophysicist Moh El-Naggar and graduate student Yamini Jangir as they examine microbes found in an old gold mine in the Black Hills of South Dakota. The story looks at the history of electron-eating microbial research and suggests how an increased understanding could tell us about life that may grow on other mineral surfaces on Earth, Mars, and beyond.

    The research was supported by the NASA Astrobiology Institute.