Studies in Surface Science and Catalysis, vol. 153, pp. 295-298
The effect of different CO2 concentrations on the growth and photosynthesis of Spirulina platensis NIES 46 was examined in terms of cell growth and photosynthetic parameters. Under 0.01% CO2, growth stopped after the depletion of the dissolved inorganic carbon and the cell yield was low. The cells grown under 0.07% CO2 exhibited no change in their growth rate when compared with the 0.03% CO2-grown culture, yet the cell yield increased from 1.2 to 3.6 g/l. The cells under 1% CO2 showed the lowest growth, even though the inorganic carbon remained at 50-60 mg/l and pH 7.5-8.0. The photosynthetic rates under 0.03 and 0.07% CO 2 were higher than those under 0.01 or 1%. Accordingly, among the tested CO2 concentrations, 0.07% CO2 was found to be the best for a high-density culture of S. platensis NIES 46.