Production of products by engineered bacteria is increased by regulating cellular respiration. Cellular respiration is controlled by reducing electron transfer enzyme activity. Some examples of electron transfer enzymes include NADH dehydrogenases, Succinate dehydrogenases, ubiquinone synthesis, cytochrome O, and cytochrome D. In one example, deletion of UbiCA prevents respiration. Respiration can the be controlled by addition of ubiquinone or expression of ubiCA.