HR: 13:40h
AN: B23D-01 INVITED     [Abstracts]
TI: Molecular Ecology of Carboxylic Acids in Hydrothermal Environments
AU: * Matsuno, K
EM: CXQ02365@nifty.com
AF: Nagaoka University of Technology, Kamitomioka, Nagaoka, 940-2188 Japan
AB: Hydrothermal environments in the primitive ocean on the Earth must have played an important role for harnessing a molecular ecology processing various carbon through-flows in the pre-RNA world. Even carboxylic acids alone could have maintained a primitive evolutionary ecology near hot vents on the seafloor. We examined whether the citric acid cycle could run in a simulated hydrothermal environment with the aid of neither reducing agents nor enzymes of biological origin under the premise that pyruvate was already available. When the major carboxylic acid molecules constituting the citric acid cycle including pyruvate were prepared in a flow reactor and the reaction fluid was circulated between hot and cold regions in a cyclic manner, the member molecules of the cycle were found to increase with the operation of the reactor. The cycle was found robust enough to synthesize the member molecules from within even in the face of adverse or hostile disturbances from the outside. The cycle was oxidative instead of being reductive, and the effective oxidant was water molecules. Underlying the operation of a molecular ecology running on the oxidative citric acid cycle is the physical pruning principle of the faster temperature drop going with the greater stored latent heat applied to any reactants crossing sharp temperature gradients.
DE: 1055 Organic and biogenic geochemistry
DE: 4811 Chemosynthesis
DE: 5215 Origin of life
DE: 8424 Hydrothermal systems (0450, 1034, 3017, 3616, 4832, 8135)
SC: Biogeosciences [B]
MN: Fall Meeting 2005