We published our second paper about C.necator in AEM which uses a barcoded transposon library to study its energy metabolism. This is not only a continuation of our previous work but also a systematic survey in the spirit of the landmark paper by R. Cramm, 2008 – in this extensive review, the author meticulously collected all known information about the energy metabolism of this interesting organism. Our work investigated the relative importance of all formate dehydrogenases, hydrogenases, and electron transport chain complexes experimentally, with several remarkable findings. This study was a fruitful collaboration between three groups that I am sincerely grateful for, Paul Hudsons lab, Oliver Lenz’ lab, and Emmanuelle Charpentier’s lab.