Acetogens are a group of bacteria that can metabolise formate. For example, they form acetic acid -- an important basic chemical. If these bacteria were manipulated to produce ethanol or lactic acid, a comprehensive circular economy for the greenhouse gas CO2 could be realised. To ensure that the process is sustainable, the CO2 is extracted directly from the air and converted to formate using renewable energy. To find out how exactly formate can be utilised by the Acetobacterium woodii (short: A. woodii), a team led by Stefan Pflügl from the Institute of Chemical, Environmental and Bioscience Engineering at TU Wien investigated how the bacterium metabolises various substrates -- including formate. Furthermore, the researchers used a metabolic model to study how A. woodii could be genetically modified to produce substances other than acetic acid.