Origins of Life – How did the first cells live, and how did they evolve?
Life on our planet evolved approximately 4 Ga ago, but since we cannot go back in time, many open questions remain. In our group, we are interested in the metabolism of the first cells and their evolution. We are studying a group of organisms, the acetogens, that only exist in the absence of oxygen (anaerobes) and that thrive on hydrogen (H2) and carbon dioxide (CO2), producing acetate (Schuchmann and Müller, 2014). Their metabolism is assumed to be ancient, since their energy carrier H2 and their electron acceptor CO2 were readily available back then (Basen and Müller, 2017). Moreover, they use the likely first and most efficient CO2 fixation pathway, the reductive acetyl-coenzyme A pathway or Wood-Ljungdahl pathway (Martin 2020).
Physiology, Biochemistry and Biotechnology of Acetogens
Acetogenic microorganisms are truly amazing microbes. They live by eating gases and producing acetic acid, the main constituent of vinegar! Also, their metabolism is ancient, since their energy source, hydrogen gas (H2) was released billion years geologically ago-from stones, in a process called serpetinization (Russell et al., 2010). By then, oxygen was not available in the oceans or in the atmosphere. Instead, acetogens breathe carbon dioxide (CO2). This makes them an important part of the global carbon cycle, as they scavenge CO2 released by the mineralization of biomass.
We are interested the physiology, biochemistry and biotechnological application of acetogens. Currently, we are studying the redox and energy metabolism of Thermoanaerobacter kivui in a DFG-funded project (→Energy conservation in the Ech--containing thermophilic acetogenic bacterium Thermoanaerobacter kivui). Moreover, we are aiming to develop thermophilic acetogens as novel industrial platform organisms in the BMBF-funded collaborative project → “ThermoSynCon”).
Russell, M.J., Hall, A.J., and Martin, W. (2010) Serpentinization as a source of energy at the origin of life. Geobiology 8: 355-371.
2. Energy conservation in the Ech-containing thermophilic acetogenic bacterium Thermoanaerobacter kivui (DFG BA5757/2-1)
Energy conservation in the Ech-containing thermophilic acetogenic bacterium Thermoanaerobacter kivui (DFG BA5757/2-1)
3. ThermoSynCon – “Development of thermophilic microorganisms for syngas conversion to biobased fuels and chemicals
ThermoSynCon – “Development of thermophilic microorganisms for syngas conversion to biobased fuels and chemicals