Biological Properties,β-carotene Accumulation Rule And Mechanism Under The Stress Of Dunaliella Salina

Dunaliella salina is a valuable unicellular halotolerant green alga. It mostly distribute in some salt fields and oceans, is the most extreme halotolerant alga in the world. The halotolerant chlorophyta Dunaliella salina is well known due to its ability to produce large quantities of β -carotene under defined conditions of stress. By common consent, it is a natural source to produce β -carotene. The present study is important to understand the whole stress-resistant machanism and the level of mutiple stress-resistant in Dunaliella. Through exploring under the stress the relation of growth properties with β -carotene accumulation of Dunaliella, we determined the β -carotene formed rule and machanism. The result showed: (1) This study scaned the wavelenth of D.salina, confirmed that it has optimum absorbance in 654nm. The number of D.salina cells per unit volume is relative with its absorbance of 654nm in correlation function. (2) We have studied Dunaliella's bfological properties, included its tolerance in different pH, its growth under 10-60 N/P. This report can give us a general idea of the state of Dunaliella's live in a higher temperature, a cool environment and without illumination. (3) This study investigates cell growth and accumulation of β -carotene of D.salina, were established basis on series of experiment with different concentration under the normal conditions. Results showed that the algal cellular maximum content of β-carotene was obtained at defined stress conditions. The β-carotene /chlorophyll ratio arrived the largest value, but its growth rate is limited under these condition. Based on the above results, the controlled mechanism and its effect on these stressfor available cell accumulation of β-carotene was thus discussed. (4) We analysis that β -carotene accumulation of seven strains Dunaliella in different stress conditions. The seven strains were grown in such culture conditions to examine the different β-carotene production. So we can further investigate the rule of β -carotene accumulation in these stress, and select the best valuable strain in commercial production of β -carotene. (5) In order to explore the molecular mechanism of D.salina β -carotene accumulation, we studied that the protein expression difference in some physiological stress which β -carotene accumulation is highest. We report a 15kD special strip in these conditions, initially confirm it is relate with β-carotene accumulation.