The effect of growing Dunaliella tertiolecta microalgae using CO2 from brewing on the production of lipid and carotenoid-rich biomass. An integrated system of microalgae photobioreactors and yeast fermenters was used, thus providing biological CO2 continuously to the microalgae culture. Yeast cultures were first carried out in fermenters using synthetic medium. With a step-wise increasing glucose concentration from 20 to 80 g L−1, the CO2 that came from 24 h yeast cultivation gave the highest biomass formation, carotenoids and lipid contents, and productivities by the microalgae. Reproduction of these experiments using beer fermentation instead of synthetic medium was carried out using different volumes of wort coupled to microalgae cultivations.