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Carotenoid astaxanthin is a concern, because of its excellent coloring ability of the body to be widely used in the feed and aquaculture industries. Astaxanthin has a strong free radical scavenging and antioxidant capacity in food, medicine and other aspects have broad application prospects. Microorganisms can synthesize astaxanthin in nature, Fife yeast has a short fermentation period, culture environment is easy to realize the advantages of high density culture, is the ideal source of natural astaxanthin. Currently the main research focus is the breeding of high-yielding strains and fermentation process optimization. This study add sugar metabolites Fife yeast fermentation process, compares the six sugar metabolites added sodium pyruvate, sodium lactate, glycerol, sodium acetate, sodium citrate, and ethanol in yeast fermentation process for the Fife cells Growth and astaxanthin synthesis; examine the concentration of sodium lactate, initial sugar concentration of dissolved oxygen conditions, as well as sodium lactate add time to the growth and impact of astaxanthin synthesis Fife yeast cells; explained from changes in metabolic flux sodium lactate yeast producing astaxanthin in Fife. The experimental results showed that the lactate, sodium acetate, sodium citrate, ethanol, in low concentrations can promote cell growth and astaxanthin accumulation, but the high concentration of sugar metabolites did not promote the fermentation process effect, sodium acetate, ethanol, glycerol, etc. or even may inhibit the growth of of Fife yeast cells. 2 g / L sodium lactate on cell growth have a certain extent, but can significantly improve the production of astaxanthin, under this condition, the Fife yeast cell yield was 4.07 g / L, only 79.2% of the control group, The Astaxanthin unit yield up to 544μg / g DCW, an increase of 15.8% compared with the control group. By changing the the shake flasks medium medium volume examines different dissolved oxygen levels of sodium lactate fermentation medium supplemented with 2 g / L sodium lactate, Fife yeast dissolved oxygen demand decrease in dissolved oxygen under conditions of low astaxanthin yield essentially unchanged. Sodium lactate early in the fermentation, and help to promote the synthesis of astaxanthin, adding 2 g / L sodium lactate, astaxanthin volume yield of 2.20 mg / L in the fermentation of 24 h, 22.7% higher than the control group. Initial sugar concentration is not significantly affected the role of sodium lactate. 7 L fermentor experiments validate the promoting effect of sodium lactate, have been a significant promotion in late exponential phase flow plus a mixture of glucose and sodium lactate solution, astaxanthin synthesis and cell yield. Astaxanthin yield up to 17.7 mg / L, a 16.8% increase compared with the control group, cell production rate in late exponential phase up to 45.0 g / L, 151% of the control. The role of sodium lactate, PP pathway enhanced the EMP pathway weakened. Because astaxanthin synthesis requires a lot of acetyl coenzyme A and energy, while the lactic acid in the effect of lactate dehydrogenase can directly into the latter half of the metabolic network, so the flux of acetyl coenzyme A and into the TCA cycle flux obtained a significantly strengthened, so as to promote the synthesis of astaxanthin.
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