Review article from the ERA Chair and collaborators from The University of Queensland published in the top journal Current Opinion in Biotechnology focuses on advances in analytical tools and metabolic modelling for unravelling the metabolism of gas-fermenting clostridia, termed acetogens, that have helped to guide industrial gas fermentation processes. Specific analytical techniques are also highlighted that need to be improved in order to enable more rational synthetic biology designs of acetogen cell factories towards a circular bioeconomy.