The Release of Energy During Protein Synthesis at Ultramafic-Hosted Submarine Hydrothermal Ecosystems

There are fundamental geochemical reasons why environments surrounding submarine hydrothermal systems are primary productivity hotspots compared with the majority of the seafloor, or with conditions deep in seafloor sediments. As reduced hydrothermal fluids mix with oxidized seawater, elements in incompatible oxidation states are brought together. The resulting rich supplies of disequilibria can be dissipated by primary productivity over wide ranges of temperature and pressure. Synthesis of many amino acids is an energy-releasing process as fluids from submarine ultramafic-hosted hydrothermal systems mix with seawater, raising questions about the overall energetics of protein synthesis. Here we show that protein synthesis is also an energy-releasing process in seawater-hydrothermal fluid mixtures in ultramafic-hosted systems, and consider some implications for microbial metabolism, biogeochemical cycles, hydrothermal ecosystem dynamics, and the emergence of life at submarine hydrothermal systems.