Astaxanthin production by Haematococcus pluvialis under various light intensities and wavelengths

The key factors for high-density Haematococcus pluvialis cultures and conditions for astaxanthin induction were examined to maximize astaxanthin production. Light intensity was found to be the most important factor, and thus experiments were carried out using different light sources and intensities. A high cell density of over 2.7 g/1 was obtained at 75 muE/m(2)/s, whereas a much lower cell concentration (<1.0 g/1) was obtained with lower light intensities (15 - 30 muE/m(2)/s). A high light intensity and the supplement of 470 ran photons had a more dramatic effect on the final astaxanthin concentration and per cell astaxanthin content. A maximum astaxanthin concentration of 6.5 mg/l was obtained at a light intensity of 160 muE/m(2)/s, whereas only 1.3 and 0.7 mg/l were obtained at 30 and 15 muE/m(2)/s, respectively. A supplement of 470 nm photons enhanced the carotenoid and chlorophyll formation.