@article{Thuan_Thuy_2014, title={Determination of the pigment carotenoid astaxanthin content in the cells of the yeast strain Phaffia rhodozyma NT5 used as additive foods in aquaculture}, volume={29}, url={https://vjs.ac.vn/index.php/vjbio/article/view/5364}, DOI={10.15625/0866-7160/v29n1.5364}, abstractNote={<p>Astaxanthin is the main carotenoid pigment found in aquatic animals. salmonid, sea breams and shrimps cannot synthesize astaxanthin, therefore, dietary astaxanthin is the only source of body astaxanthin.</p> <p>The yeast <em>P. rhodozyma</em> is one of the new natural astaxanthin sources of biomass product of the Phaffia yeast is used as a color additive in aquaculture feeds to increase pink color of salmonid flesh.</p> <p>The culture conditions, the astaxanthin content of the yeast <em>P. rhodozyma</em> NT5 isolated from Vietnam and the influence of astaxanthin extracting methods were studied. The results showed that:</p> <p>1. The growth of the yeast strain <em>P. rhodozyma </em>NT5<em> </em>in shaked flasks under cultural conditions (concentration of sucrose 2%, pH = 5; temperature 22<sup>0</sup>C ) reached its maximum value after 120 hours (11.42 g/l). The astaxanthin pigment formation began at 24 hours (33.32 mg/g) and the yield of the astaxanthin pigment reached its highest level (285.4 mg/g) after 120 hours. The cell mass were not significantly different from day 3 to day 5.</p> <p>2. The mechanical method of the cell wall rupture with glass balls having a diameter of 2mm showed the best results. After 30 minutes, 92% of yeast cells were ruptured compared with 75% ones by glass powders. The rupture of the fresh cell walls gave better result (100% compared with 92% of dry cells).</p> <p>3. The extract of the pigment astaxanthin from fresh yeast mass with acetone + petroleum ether (PE) gave the highest effect; the astaxanthin content reached 327 mg/g dry mater. At the time, astaxanthin content extracted with acetone or ethanol reached only 296.4 mg/g and 118.96 mg/g, respectively.</p>}, number={1}, journal={Academia Journal of Biology}, author={Thuan, Tong Kim and Thuy, Tran Thanh}, year={2014}, month={Nov.}, pages={82–88} }