Ancient Microbes Reveal How Life Generated Energy Without Oxygen: A Breakthrough in Understanding Early Life on Earth

Research led by Professor Volker Müller at Goethe University Frankfurt has elucidated how primordial microbes, thriving in oxygen-free environments like deep-sea hot springs, generate energy. These microbes combine carbon dioxide and hydrogen to form acetic acid, a process that activates a mechanism pumping sodium ions out of the cell. This creates a sodium gradient, which, when reversed, drives a molecular turbine (ATP synthase) to produce ATP, the universal energy currency. The Rnf complex, a collection of membrane-embedded proteins, plays a crucial role in this process, shunting electrons from hydrogen to carbon dioxide. Using cryo-electron microscopy and molecular dynamics simulations, scientists visualized the Rnf complex and identified an iron-sulfur cluster that attracts sodium ions, facilitating their expulsion from the cell. This discovery not only enhances our understanding of early life forms but also holds potential for carbon capture technologies and the development of new antibacterial drugs by targeting similar respiratory enzymes in pathogens.