Scientists have a study in scenedesmus obliquus. They analysis the carotenoid accumulation in algal cells and astaxanthin synthesis. Meanwhile, they involve in study of cell morphology, structure and physiological changes in carotenoid synthesis and metabolism processes. They also discuss about the function of astaxanthin in the cells. The main findings are as follows. In addition, patients and their family members can get astaxanthin price from the internet and hospitals.

There are two steps to cultivate scenedesmus obliquus to induce carotenoid accumulation. The specific inducing conditions include: the nitrogen concentration of 0.75g / L, the light intensity of 180μmol m-2 s-1, temperature of 35 ° C, salt concentration 0.4g / L, pH value is maintained at 7. Analysis showed that the carotenoid composition in the cells of Scenedesmus obliquus, including lutein, a new flavin-born carotenoids and sea urchins ketone, canthaxanthin, 3'-hydroxy-sea urchin ketone, marigold flavin, marigold red factors and astaxanthin and secondary carotenoids. Intracellular astaxanthin biosynthetic pathway from β-carotene into canthaxanthin or 3'-hydroxyl sea urchin ketone by sea urchins ketone, canthaxanthin and then converted to the marigold red pigment; 3'-hydroxy sea urchin ketone can be transformed into red pigment of marigold or calendula flavin; marigold red pigment and marigold flavin eventually turned into a three biosynthetic pathway for astaxanthin; Astaxanthin synthesis process, chlorophyll, lutein and flavin content decreased, and changes in the content of chlorophyll and astaxanthin content was negatively correlated.

After the removal of the stress conditions, the intracellular pigment composition has also changed. The secondary carotenoids hydrolysis of astaxanthin monomer disappeared, only detected astaxanthin ester; including sea urchins ketone, canthaxanthin and marigold red pigment astaxanthin precursors have undergone hydrolysis. Born carotenoids such as chlorophyll and lutein again become the main component of the pigment. According to the experimental results, it infers that astaxanthin has three ways in the metabolic process: The first part is esterified to generate astaxanthin monoester or diester; together with most of the secondary carotenoid algal cells in some way re-use: three along the path of the similar xanthophyll cycle, reverse synthesis of lutein in photosynthesis.

The photosynthetic physiology of the cell has changed greatly in the process of the cells to synthesize astaxanthin. However, when experimental conditions change, remove stress, the photosynthetic activity of cells is reversed. Accompanied by the hydrolysis of secondary carotenoids, photosynthetic rate of the cells was even higher than the initial level stress; a strong reduction of cell respiration rate, only 3.98μmol • O2 • mg the-1chla • h-1. Changes of the photosynthetic activity of these two processes in the cell showed that the secondary carotenoids and astaxanthin of cells with light protection can reduce the photosynthetic activity through the barrier effect against high light damage.

Cells by light microscopy and electron microscopy, cell morphology and structure have undergone significant changes. The normal growth of scenedesmus obliquus is stereotyped groups of four or eight cells, the cells were spindle-shaped. Single or two cell groups in the process of accumulation of secondary carotenoids, the cells begin to become round or oval; cell color from green to yellow or brown. The cell ultrastructure of the biggest changes is the formation of a large number of fat body and gradually occupied most of the intracellular space; the fat body of the nucleus, chloroplasts and other organelles are wrapped up, and transferred to the cell center or the side. In the whole process, the chloroplast and thylakoid structure, morphology remain intact. This shape change is reversible, with the hydrolysis of the fat body, cell morphology and structure of the gradual return to normal. This change also shows that cosmetics material astaxanthin has a physical protective effect for organelles especially chloroplast.

Algal cells, accumulates carotenoids. At the same time, growth and proliferation are also affected. The experimental results show that dry weight of the cells in stress increased by 18.9% within 48 hours. It is much higher than normal growth cells in the same period. The intracellular protein and RNA levels are decreased in varying degrees. And it is significantly lower than normal growth of cells, thus indicating that growth is inhibited. The cell numbers and the intracellular DNA content appeared to decline and it is lower than the control group cells. When conditions change, hydrolysis of secondary carotenoids occurs and these physiological processes are recovered. These results suggest that normal cell division and proliferation are inhibited by stress conditions. The increasing of cell volume and dry weight is closely related with accumulation of astaxanthin in carotenoid.