5:15 PM - 6:45 PM
[U11-P10] Reproduction of catalysis by sulfide minerals in the flow-reactor simulating ancient deep-sea alkaline hydrothermal system
Keywords:Hydrothermal vent, Chemical evolution, Origin of life, Prebiotic metabolism, Flow-reactor, Inorganic catalyst
In considering the origin of life, organic materials must be accumulated through abiotic synthetic reactions. We have proposed the electrochemical evolution hypothesis to explain the emergence of prebiotic metabolic pathways in ancient deep-sea hydrothermal vents. The metal sulfides were produced by the mixing reactions between hydrothermal fluid and seawater, and acted as inorganic catalysts for organic chemical reactions. The reducing power was continuously supplied from the alkaline hydrothermal fluid through the metal sulfide minerals. Previous studies suggested that the stronger negative potential produced by an artificial external power supply reduced sulfide minerals then the reduced minerals promoted various organic reduction reactions in the central metabolic pathways. However, these reactions, such as sulfide mineral formation, sulfide mineral reduction, and organic reduction reactions, were observed separately in the different batches, but not sequentially in one reactor. Therefore, the primary objective of this study is to reproduce the continuous reactions in a flow-reactor simulated ancient hydrothermal environmental conditions. Sulfide ion-rich alkaline hydrothermal fluid and metal ion-rich acidic seawater were prepared. The two solutions were flown through the reactor under the control of flow rate, pressure, and temperature, and were mixed in a porous glass pipe installed in the mixing unit. A chimney wall mainly composed of metal sulfide were formed on the surface of the porous glass, which is expected to catalyze synthesis of biomolecules. In this presentation, we will report on the recent research progress focusing on the amino acid synthesis via the reductive amination from organic acids on the sulfide metals.