The Optimization Of Culture Conditions To Dunaliella Sp. At Salt Lake In Yunchen, Shanxi

Dunaliella sp. is capable of accumulating large amounts of P-carotene up to 14% of their dry weight under defined stress conditions. Dunaliella sp. is the best commercial source of natural β-carotene. β-carotene, a plant precursor to vitamin A, plays an important role in disease treatment and food security. It has a profound effect on cell proliferation and producing β-carotene to developing the research on culture Dunaliella sp. In this study, the single factor, orthogonal experiments and added exogenous substances to medium were performed to optimize the cultivating conditions for Dunaliella sp. which was collected from salt lake in Yuncheng, Shanxi, China. The main results showed that:(1) Through the single factor and orthogonal experiments, temperature, NaCl concentration, N, P and Fe were studied for effects to the cell density and β-carotene contents of Dunaliella sp. The cell density and β-carotene contents of Dunaliella sp. presented a good linear relationship with A654nm and A453nm respectively. The cell density and P-carotene contents of Dunaliella sp. were measured using the method of optical density which was simple, accurate and efficient. Dunaliella sp. was cultured under 20～25℃ and 1.0～2.0mol/L (NaCl) that were conducive to the cell proliferation and β-carotene accumulation. A high concentration of NaNONaH2PO4·2H2Ocould not conducive to cell proliferation and accumulation of P-carotene, and the concentration of FeC6H5O7 had no significant effect on cell proliferation and accumulation of β-carotene. The optimum concentrations of NaNO3,NaH2PO4·2H2O and FeC6H5O7 for cell proliferation were 0.2200g/L,0.0256g/L and 0.00100g/L; 0.6200g/L,0.0256g/L and 0.0010g/L was optimum concentrations for β-carotene accumulation. The medium for cell proliferation and β-carotene accumulation of Dunaliella sp. were optimized for lay the theoretical foundation of future development and utilization of local high β-carotene production algae strains.(2) In this study, the cell proliferation and β-carotene accumulation of Dunaliella sp. were researched by adding different concentrations of glucose oxidase and cytochrome C to the medium. To grow cells to a minimum or maximum density when the concentrations of glucose oxidase were10mg/L and 9mg/L respectively. There was no significant effect among many concentrations; there was the highest β-carotene content and significant effect on concentration of glucose oxidases that was 9mg/L. The experiment of cytochrome C was done under the experiment of glucose oxidases. The optimal concentration of cytochrome C for cell proliferation was 2μmol/L which had a significant effect; 1μmol/L was optimum concentration for accumulation of β-carotene and it had a significant effect.