Spirulina platensis produces nutraceutical product C-phycocyanin (C-PC) and 
simultaneously mitigates CO2 emissions during its growth. Using a designed 
flat-type photobioreactor, the S. platensis biomass production was markedly 
enhanced, leading to a CO2 removal rate and a biomass concentration of 0.23 
g/L/d and 2.25 g/L, respectively. The cell growth, CO2 fixation rate and C-PC 
production of S. platensis were investigated when it was cultivated under 
different irradiation conditions. As the light intensity increased from 100 to 
700 μmol/m(2)/s, the overall biomass productivity, CO2 consumption rate and 
maximal C-PC productivity increased significantly to 0.74, 1.53 and 0.11 g/L/d, 
respectively. After determining the suitable light intensity, the nitrogen 
concentration was also adjusted to further enhance the performance of CO2 
fixation and C-PC production. The results show that with an optimal nitrogen 
concentration of 0.045 M, the CO2 consumption rate and maximal C-PC productivity 
were further increased to 1.58 and 0.13 g/L/d, respectively.