The Wood-Ljungdahl pathway (WLP) is the only pathway of CO2 fixation that is coupled to the synthesis of ATP and thus allows growth on microbes on H2 + CO2 by producing acetate. Some bacteria also produce, in minor amounts, ethanol or even C6 acids or alcohols. I will describe how metabolic engineering allows for the production of formate or lactate and how soluble “CO2” analogues such as formate and methanol are used to improve production of added-value compounds.
References
[1] Jimyung Moon, Lara M. Waschinger, Volker Müller (2023) Lactate formation from fructose or C1 compounds in the acetogen Acetobacterium woodii by metabolic engineering. Appl. Microbiol. Biotechnol. 107, 5491-5502 (2023). https://doi.org/10.1007/s00253-023-12637-7.
[2] Jimyung Moon, Anja Schubert, Lara M. Waschinger, Volker Müller, Reprogramming the metabolism of an acetogenic bacterium to homoformatogenesis. ISME J., 17, 984-992 (2023). https://doi.org/10.1038/s41396-023-01411-2.
[3] Helge M. Dietrich, Ricardo D. Righetto, Anuj Kumar, Wojciech Wietrzynski, Raphael Trischler, Sandra K. Schuller, Jonathan Wagner, Fabian M. Schwarz, Benjamin D. Engel, Volker Müller, Jan M. Schuller, Membrane-anchored HDCR nanowires drive hydrogen-dependent CO2 fixation. Nature 607, 823-830 (2022). https://doi.org/10.1038/s41586-022-04971-z.
[4] Fabian M. Schwarz, Jimyung Moon, Florian Oswald, Volker Müller, Biological hydrogen storage and release through multiple cycles of bi-directional hydrogenation of CO2 to formic acid in a single process unit. Joule 6, 1304-1319 (2022). https://doi.org/10.1016/j.joule.2022.04.020.
[5] Kai Schuchmann, Volker Müller, Direct and reversible hydrogenation of CO2 to formate by a bacterial carbon dioxide reductase. Science 342, 1382-1385 (2013). https://doi.org/10.1126/science.1244758.
Professor Volker Müller is Head of the Department of Molecular Microbiology and Bioenergetics at Goethe University, Frankfurt. His research interest is the metabolism and biochemistry of anaerobic microorganisms with a focus on acetogenic bacteria. His group discovered how these bacteria make a living during autotrophic and heterotrophic growth, characterized the enzymes involved in bioenergetics, carbon and electron flow and redox homeostasis. His group established the use of acetogens to capture and store hydrogen as well as carbon dioxide. The lab also uses archaea to study the metabolic processes that allow microbial life under extreme energy limitation and that couple CO2 fixation to ATP synthesis. He has directed a European-wide ERA-IB Network on industrial applications of acetogenic bacteria. He has co-authored close to 300 papers and was awarded in 2016 one of the prestigious Advanced Investigator Grants of the European Research Council to work on “Acetogenic bacteria: from basic physiology via gene regulation to application in industrial biotechnology”. In 2022 he was awarded with a Reinhart-Koselleck project of the German Research Foundation (DFG) for his work on the role of cytochromes in acetogens and in 2023 he was elected as fellow of the American Academy of Microbiology. For further information: www.mikrobiologie-frankfurt.de
