Effects of Medium Replacement on Cell Density and Astaxanthin Accumulation in H. Pluvialis Illuminated by LED Lamps

Abstract

Haematococcus pluvialisis is one of the potential candidates for production of astaxanthin. Growth characteristics of H. pluvialis in batch run and medium replacement runs were measured. A two-stage process was employed for biomass and astaxanthin synthesis by this alga. During the first stage, medium was replaced several times every day to achieve high cell concentration. When the replacement was stopped, the light illumination was switched from red LEDs at 8μmol photons m^-2 s^-1 to blue LEDs at 12µmol photons m^-2 s^-1 to stimulate the accumulation of astaxanthin without decreasing in the cell numbers by death of the cells. H. pluvialis exhibited relatively high cell concentration in the first step and reached to about 1.5 mg-dry cell/cm³ and accumulated up to 65 µg/cm³ astaxanthin in the second stage, which are higher than those reported in literature.