INITIAL STUDIES ON THE EFFECTS OF STRESS CONDITIONS ON ASTAXANTHIN ACCUMULATION OF HAEMATOCOCCUS PLUVIALIS

Induction of astaxanthin accumulation in Haematococcus pluvialis by three stress conditions was studied,which including nitrogen deficiencies,salt stress and illumination with different wavelengths.Nitrogen deficiencies(NaNO_3≤0.012 g/L)were not favorable to the growth of the H.pluvialis,but they could promote the astaxanthin accumulation in the planospore and reduce the ratio of aplanospore to no more than 15%.High salinity could induce the production of astaxanthin in H.pluvialis in a short time,with the highest levels of astaxanthin under the NaCl concentration of 2.5 g/L.However,such increases in salinity were accompanied by high rates of cell mortality.The illumination with different wavelengths has quite different effects on the growth and astaxanthin accumulation of H.pluvialis:red light was favorable to the growth of the alga,while blue light enhanced the astaxanthin production.The effects of the illumination with different wavelengths enhanced in the following order:blue light,red light,green light and white light.