Genetically engineered cells and methods are presented that allow for the production of various value products from CO2. Contemplated cells have a CBB cycle that is genetically modified such that two molecules of CO2 fixed in the CBB cycle can be withdrawn from the modified CBB cycle as a single C2 compound. In contemplated aspects a CBB cycle includes an enzymatic activity that generates the single C2 compound from a compound of the CBB cycle, while further modifications to the CBB cycle will not introduce additional recombinant enzymatic activity/activities outside the already existing catalytic activities in the CBB cycle.