The cyanobacterium Anacystis nidulans R2 is a photosynthetic procaryote grown only under inorganic carbon conditions. We studied cell-growth (CO 2 -removal) characteristics of this strain, cultivated photoautotrophically at 30°C in 1.1 dm 3 in airlift bioreacters. The highest growth rate of 0.046 h - 1 was achieved when the culture was illuminated at 8 klx and sparged with 5% CO 2 (volume/volume). But, the level of attainable cell mass concentration was not greatly affected by the CO 2 concentration between 5% and 30%. These results are suggestive of an opportunity to integrate this bioreactor as a technique for direct CO 2 removal from boiler flue gas.