CO2 biofixation by Synechococcus elongatus from the power plant flue gas under various light–dark cycles

Carbon dioxide emission, which acts as one of the major agents of greenhouse gases (GHG), has significant effects on global warming. Nowadays, there is a considerable global tendency toward decreasing the amount of GHG emissions to the atmosphere. In the present study, a simulated power plant flue gas (Be’sat, Power Plant, Tehran) with a constant injection rate of 21.41 cm3 s−1, including 10% CO2, 7% O2 and 83% N2 , was injected to the Synechococcus elongatus culture under two different light–dark (L/D) cycles: 24-0 and 16-8. Additionally, the biomass productivity and the CO2 biofixation rate by microorganisms were investigated. The highest biomass productivities were recorded as 0.68 and 0.52 g L−1 d−1 for 24-0 and 16-8 L/D cycles, respectively. Furthermore, the maximum rate of the CO2 biofixation was 1.26 g L−1 d−1 for the 24-0 L/D cycle and 0.98 g L−1 d−1 for the 16-8 L/D cycle during the cultivation.