One-carbon feedstocks such as formate could be promising renewable substrates for sustainable microbial production of food, fuels and chemicals. Here we replace the native energy-inefficient Calvin-Benson-Bassham cycle in Cupriavidus necator with the more energy-efficient reductive glycine pathway for growth on formate and CO(2). In chemostats, our engineered strain reached a 17% higher biomass yield than the wild type and a yield higher than any natural formatotroph using the Calvin cycle. …