Study On Location Of Astaxanthin Accumulation And Screening Model Of Astaxanthin-Hyperproducing Strains Of Phaffia Rhodozyma

Astaxanthin is an oxycarotenoid and has wide applications in food, feed, medicine and cosmetics for its excellent biological characteristic. Phaffia rhodozyma produces the most industry prospect in production of nature astaxanthin with biological resources. Astaxanthin- hyperproducing strains play a key role in fermentation industry, however, new screening model is a vital factor for further improving astaxanthin content. According to the situation of breeding astaxanthin-hyperproducing strains at home and abroad, this paper study the screening model of astaxanthin-hyperproducing strains by studying the location and cell cycle of astaxanthin accumulation in Phaffia rhodozyma and by means of synthesis mechanism of astaxanthin.The study of location of astaxanthin accumulation is performed by transmission electron microscopic and laser scanning confocal microscope. The results indicate that astaxanthin mainly accumulate in the lipid globule around the membrance. By using flow cytometry to analysis the cell cycle of Phaffia rhodozyma, we find astaxanthin is synthesized in G1 phase of cell cycle. According to above results, we guess that the metabolic regulation of astaxanthin synthesis has a important relationship with fat synthesis, respiratory metabolism, by-product accumulation of carbohydrate metabolism and active oxygen generation.On the basis of above biochemical characteristics of Phaffia rhodozyma, how to screen astaxanthin-hyperproducing strain is studied byβ-ionone, fluvastatin, ethanol, Cu2+, cimetidine, Fe3+, sodium nitrite, sodium acetate and glycerol respectively. The results show that the model set up byβ-ionone, fluvastatin, ethanol, Cu2+, cimetidine, Fe3+, sodium nitrite can be used to screen astaxanthin-hyperproducing strains and the screening concentration is 370 mg/L, 224μg/mL, 2.5% (volume percentage concentrations), 100μg/mL, 50μmol/L, 5000μmol/L, 4400μmol/L.Above research results not only are used to scereen astaxanthin-hyperproducing strains, but also can provide evidence for establishing effective metabolic regulation strategy of improving astaxanthin by fermentation. Which can further improve the level of astaxanthin product by fermentation.