Maximization of Astaxanthin Production from Green Microalga Haematococcus pluvialis Using Internally-Illuminated Photobioreactor

An internally-illuminated photobioreactor was designed to maximize the astaxanthin production by Haematococcus pluvialis. Four optimization steps were conducted: 1. light wavelength 2. light intensity 3. astaxanthin formation and 4. astaxanthin extraction methods. Efficient biomass production of H. pluvialis of 4.58 ± 0.15 × 10 5 cells/ml and dry biomass of 520 ± 12.5 mg/L was accomplished under red LED light (660 nm) with 70 μmol m -2 s -1. Besides, the biomass production can be optimized to 5.31 ± 0.15 × 10 5 cells/ml and dry biomass of 680 ± 10.5 mg/L under 140 μmol m -2 s -1 in the light intensity of 70-210 μmol m-2 s-1. Furthermore, the astaxanthin accumulation was significant with 7 days encystment under 140 μmol m -2 s -1 blue LED lights. For extraction method, using hydrochloric acid could obtain the highest astaxanthin yield of 3.85 ± 0.05% (% to dry weight). Further studies were proposed whatever such photobioreactor can be applied to different microalgal strains