Spark of Life: Role of Electrotrophy in the Emergence of Life

The emergence of life has been a subject of intensive research for decades. Different approaches and different environmental cradles have been studied, from space to the deep sea. Since the recent discovery of a natural electrical current through deep-sea hydrothermal vents, a new energy source is considered for the transition from inorganic to organic. This energy source (electron donor) is used by modern microorganisms via a new trophic type, called electrotrophy. In this review, we draw a parallel between this metabolism and a new theory for the emergence of life based on this electrical electron flow. Each step of the creation of life is revised in the new light of this prebiotic electrochemical context, going from the evaluation of similar electrical current during the Hadean, the CO2 electroreduction into a prebiotic primordial soup, the production of proto-membranes, the energetic system inspired of the nitrate reduction, the proton gradient, and the transition to a planktonic proto-cell. Finally, this theory is compared to the two other theories in hydrothermal context to assess its relevance and overcome the limitations of each. Many critical factors that were limiting each theory can be overcome given the effect of electrochemical reactions and the environmental changes produced.

Automated summary

The emergence of life has been extensively studied, with recent attention given to the discovery of natural electrical current in deep-sea hydrothermal vents. This new energy source, known as electrotrophy, has implications for understanding the transition from inorganic to organic life forms. In this review, the role of electrochemical reactions in each step of life's formation is explored, including the evaluation of electrical current in the Hadean era, CO2 electroreduction into a prebiotic primordial soup, proto-membrane production, nitrate reduction inspired energetic system, proton gradient, and the transition to a planktonic proto-cell. The theory is compared to other hydrothermal theories to assess its relevance and ability to overcome limitations.