Microalgae perform oxygenic photosynthesis and are capable of taking up a large amount of CO2, using an inducible CO2 concentrating mechanism (CCM), and fixing CO2 into higher compounds. These characteristics make the microalgae potentially useful for removal and utilization of CO2 emitted from industrial plants and, generally, the usage of photosynthetic microorganisms has increased and significantly improved as a solution for CO2 emissions. In this light and based on previous research using Anabaena cylindrica IAM M1 and Spirulina platensis IAM M 135, enhancement was sought for CO2 fixation and biomass production by Chlorella vulgaris Buitenzorg by increasing the photon flux density concurrent with increases in culture biomass during the cellular growth phase and was compared to cultures of Chlorella grown at optimal constant illumination, with all cultures grown using Bennick basal medium, 29°C, and a flow of 1.0 atm. 10% CO2 enriched air delivered to three in serial photobioreactors of 0.200 dm3 capacity each. The results showed that increasing illumination during culture increased biomass production of Chlorella by ∼60% as well as increased CO2 fixation ability by ∼7.0%. It was also demonstrated that the non-competitive inhibition of [HCO3-] as a carbon source significantly affected the cultivation in both the increasing and constant photon flux density regimes.
- Chlorella vulgaris Buitenzong