Michael Russell’s main focus of research is to find the particular mechanisms that enabled life to emerge in an inorganic world at submarine alkaline hydrothermal vents and by what metabolic pathways. Serpentinization produces both hydrogen and methane but as our lab experiments failed to produce methane in 10,000 minutes it was concluded, against conventional thinking, that methanogenesis was not a viable protometabolic pathway. Instead we considered methane a fuel (along with hydrogen) and a source of carbon but not a waste product. A mineral membrane is considered to have separated the reduced and alkaline hydrothermal fluids at the vent from the relatively oxidized acidulous ocean and thus imposed steep gradients; electrons dropping to external electron acceptors while protons take the counter path through the membrane toward the vent fluid. What do the electrons and protons do as they drop down their respective gradients? In life it is now clear that they drive nanoengines coupling endergonic reactions with necessarily greater exergonic reactions. He and fellow Research Scientist Laurie Barge have identified green rust as a potential nanoengine that could have operated in the membrane i) to oxidize methane to a methyl group which reacts with carbon monoxide to produce acetate andii) concomitantly reduce oceanic nitrate to ammonium for aminations of carboxylic acids. We view these mineral-assisted reactions as contributing to the first metabolic pathway of life, viz., denitrifying methanotrophic acetogenesis. Aminations and polymerizations in green rust are expected to lead irreversibly to a ligand-accelerated autocatalytic pathway, and eventually to a self-informing life.
Russell Michael J., Barge Laura M., Bhartia Rohit, Bocanegra Dylan, Bracher Paul J., Branscomb Elbert, Kidd Richard, McGlynn Shawn, Meier David H., Nitschke Wolfgang, Shibuya Takazo, Vance Steve, White Lauren, and Kanik Isik. Astrobiology. April 2014, 14(4): 308-343. doi:10.1089/ast.2013.1110.
This paper presents a reformulation of the submarine alkaline hydrothermal theory for the emergence of life in response to recent experimental findings. The theory views life, like other self-organizing systems in the Universe, as an inevitable outcome of particular disequilibria.