Microalgae are the unicellular or multicellular photosynthetic microorganisms that can efficiently fix carbon dioxide (CO2) from various sources such as the environment, industrial flue gas, and some carbonate salts. In the present study, one green microalgal strain and a cyanobacterial consortium were used separately for the sequestration of CO2 at different pHs (7-11), at different initial concentrations of CO2 (5-20%), and at various inoculum sizes (5-12.5%). The maximum sequestration of CO2 was found to be 74.37 +/- 0.49% and 71.12 +/- 0.05% at 5% and 15% CO2 for green algae and cyanobacterial consortium. The biomass generated after sequestration of CO2 was utilized for the synthesis of biomolecules.