Enhanced biomass and phycocyanin production of Arthrospira (Spirulina) platensis by a cultivation management strategy: Light intensity and cell concentration

This work investigated the cultivation of Arthrospira (Spirulina) platensis BP in a photobioreactor under light intensities of 635, 980, 1300, and 2300 mu mol m(-2) s(-1), using a semi-continuous mode to keep cell concentration at optical densities (OD) of 0.4, 0.6, and 0.8. The highest productivity of biomass (0.62 g L-1 d(-1)) and phycocyanin (123 mg L-1 d(-1)) were obtained when cells were grown under a light intensity of 2300 mu mol m(-2) s(-1) at OD 0.6. At this concentration, the efficiency of energy consumption to the biomass of algae was around 2.26-2.31 g (kW h)(-1) d(-1), while, a maximum photosynthetic efficiency of 8.02% was obtained under a light intensity of 635 mu mol m(-2) s(-1) at OD 0.8. This indicates how light intensity, cell concentration, and light-dark conditions can enhance biomass and phycocyanin production, if well manipulated.