Effect of Light Quality on the Growth of Microalgae Haematococcus lacustris

Abstract

Haematococcus lacustris (formerly Haematococcus pluvialis) has been widely known as a promising natural source of astaxanthin. To produce a higher amount of astaxanthin content in H. lacustris, two major aspects are considered including increasing biomass production of green cells or enhancing astaxanthin accumulation in red cysts.  The aim of this study was to investigate the effect of light quality of Light emitting diodes (LEDs) on the growth of H. lacustris. In the present research, the effect of different light spectrum, light intensity on the growth of H. lacustris was simultaneously investigated for 11 days of cultivation period. The experiments were performed in Bold’s Basal Medium, illuminated with a circadian light/dark cycle of 16/8 and maintained at 25ºC.  A mixture of red and blue at the light intensity of 30 µmol photons m-2 s-1 was found to be the most effective light quality for growing. The highest cell density obtained with mixed red-blue illumination at the light intensity of 30 µmol photons m-2 s-1 after 9 days of cultivation was 49.57 (105 cells/ml) corresponding to the specific growth rate of 0.509 d-1.