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 the deep-sea hydrothermal vent, a new energy source is considered for the transition from inorganic to organic. This energy source is used by modern microorganisms using a new trophic type, called electrotrophy. In this review, we draw the 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 CO 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 to overcome the limitations of each one. Many critical factors that were limiting each theory can be overcome with the effect of the electrochemical reactions and the environmental changes produced.