A Thermodynamic Quirk in Marine Sediments May Explain Why We're Not All Suffocating in Methane Right Now
Presented by: Karen Lloyd, UT Microbiology
Most of the microbes buried in marine sediments have never been cultured in a laboratory, so we must design experiments to test their physiology without removing them from their natural settings. A type of archaea, called ANME-1 have been shown to oxidize methane anaerobically in a consortium with sulfate reducing bacteria through a mechanism that has not been fully characterized. However, since ANME-1 survive on very low energies, theory predicts that they should reverse their metabolism to methanogenesis when the reaction becomes exergonic in that direction. We found evidence that this occurs in the White Oak River estuary, and a re-analysis of some published literature supports our conclusions. This nimble switching between methanogenesis and anaerobic methane oxidation in natural settings suggests that, despite being relatively slow growers, these organisms are well-poised to adapt their metabolism quickly to environmental changes. The fact that they get energy from both the forward and reverse directions of a single metabolism, depending on the exergonicity of the chemical reaction, may explain how they are able to consume 99% of the vast quantity of methane that is microbially produced in marine sediments.
Monday, August 26 at 3:30pm to 4:30pm
Science and Engineering Research Facility (SERF), 307
1414 Circle Dr, Knoxville, TN 37996