Syngas is a flexible feedstock that can be used by anaerobic bacteria to produce chemicals. Here, we aim at establishing synthetic microbial consortia for the production of odd-numbered fatty acids and alcohols from syngas.
The transition towards a circular economy demands of novel industrial processes that reduce carbon emissions and ensure sustainable production of chemicals and fuels. In this context, a technology that has received increased attention within recent years is syngas fermentation. Synthesis gas, or syngas, is a mixture of mainly CO, CO2 and H2 that can be obtained from the gasification of virtually any carbonaceous material, including waste resources and lignocellulosic biomass. Syngas also constitutes an important industrial off-gas, contributing significantly to greenhouse gas (GHG) emissions into the atmosphere. Acetogenic bacteria can use this CO-rich gas as substrate, producing organic compounds such as acetic acid and ethanol. In this project, we aim at expanding the array of products to longer-chain fatty acids and alcohols than can serve as platform chemicals. Teamwork is the key to achieve this: synthetic microbial consortia can be built that combine the necessary metabolic pathways to yield the desired products.
This project builds on previous work carried out at the Laboratory of Microbiology that demonstrated the production of butyric acid (C4), caproic acid (C6) and their respective alcohols from syngas by a co-culture of Clostridium species. Here, we intend to produce the odd-numbered fatty acids valerate (C5), heptanoate (C7) – and perhaps even longer-chain fatty acids- and their respective alcohols, which are rare in nature but serve as important building blocks in the chemical industry. Following a modular approach, a propionic acid-producing bacterium will be incorporated into the existing co-culture in order to promote the production of odd-chain products.