| Haematococcus pluvialis is one of the unicell fresh water green microalgae. At stresscondition environment, Haematococcus pluvialis can systhesis astaxanthin. Economicmicroalgae Haemalococcus pluvialis CG-11 used as experimental material, and cultivated inBBM medium. The influence of the physical factors(temperature,illumination and salinity) andnutrition factors on cell biomass, chlorophyll a content, carotenoid content, dry weight andastaxanthin content of the spore cell has been studied, to find the optimum condition whichbenefit for spore cell's astaxanthin accumulation. These experiments were carried out separatelyas three single factor tests. The results showed:1) The study of different sodium acetate concentration effects on astaxanthin accumulationshowed that, the concentration range from 0.5 g/L to 1.0 g/L of sodium acetate were suitable foraccumulation of astaxanthin in the spore cell of H. pluvialis CG-11. The astaxanthin contentsignificantly superior than other condition. Astaxanthin content accounted for 3.22 percent oftotal cell biomass. It was raised 20.53 percent against the control group. 1.0 g/L of sodiumacetate concentration of inhibited the growth and bring down the astaxanthin content.2) The study of different sodium bicarbonate concentration effects on astaxanthin accumulationshowed that, the concentration range from 0.5 g/L to 1.0 g/L of sodium bicarbonate were suitablefor accumulation of astaxanthin in the spore cell of H. pluvialis CG-11. The astaxanthin contentsignificantly superior than other condition. Astaxanthin content accounted for 3.44 percent oftotal cell biomass. It was raised 27.50 percent against the control group. And unit volume ofastaxanthin content accounted for 4.23 mg/L.3) The study of different nitrogen and phosphorus concentration effects on astaxanthinaccumulation showed that, nitrogen or phosphorus deficiency condition were suitable foraccumulation of astaxanthin in the spore cell of H. pluvialis CG-11. The astaxanthin contentsignificantly superior than other condition. The astaxanthin content up to 3.69 percent of totalcell biomass.. It was raised 21.50 and 22.52 percent respectively against the control group. Andunit volume of astaxanthin content reach accounted for 5.86 mg/L in phosphorus deficiency.4) The study of different temperature effects on astaxanthin accumulation showed that, thetemperature range from 30℃to 35℃were suitable for accumulation of astaxanthin in the sporecell of H. pluvialis CG-11. The astaxanthin content significantly superior than other condition.Astaxanthin content accounted for 3.52 percent of total cell biomass. It was raised 39.69 percentagainst the control group. Any level higher or lower than 30～35℃were less better for H.pluvialis CG-11 to accumulate astaxanthin. 5) The study of different illumination intensity effects on astaxanthin accumulation showed that.the illumination intensity range from 150μmol photon·m-2·s-1 to 250μmol photon·m-2·s-1 weresuitable for accumulation of astaxanthin in the spore cell of H. pluvialis CG-11. Astaxanthincontent significantly superior than other illumination intensity. Astaxanthin content accountedfor 3.47 percent of total cell biomass. It was raised 30.93 percent against the control group. Andunit volume of astaxanthin content accounted for 5.54 mg/L at 200μmol photon·m-2·s-1.6) The study of different salinity effects on astaxanthin accumulation showed that, the salinityrange from 0.25% to 0.75% were suitable for accumulation of astaxanthin in the spore cell of H.pluvialis CG-11. The astaxanthin content significantly superior than other condition. Astaxanthincontent accounted for 3.66 percent of total cell biomass. It was raised 19.55 percent against thecontrol group. And unit volume of astaxanthin content reach to 6.75 mg/L at 0.5% salinity.
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