Study on the optimization of carotenoids production by Haloferax mediterranei

• Main Authors: Ya-Chi Chang, 張雅琪
• Other Authors: Ming-Tse Lin
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/69697079577091237077

碩士 === 大同大學 === 生物工程學系(所) === 96 === According to the results of feed-batch fermentation, below 1300 μs/cm conductivity could obtain highest yield of cartotenoid. Besides, Haloferax mediterranei could be induced more pigment when transferred to another medium that contained 5% NaCl. A statistical methodology, combining Plackett-Burman design (PBD) with method of steepest ascent and central composite design, was applied to optimize the inorganic salt components and their concentrations in liquid fermentative medium for cell growth and cartotenoids production of Haloferax mediterran. Among the eleven inorganic salts investigated with PBD, NaCl, MgCl2, and MgSO4 were selected because of their effects on the production of cartotenoids. By methods of steepest ascent analysis and central composite design, the concentrations of inorganic salts were NaCl 79.95 g/L, MgCl2 10.44 g/L, and MgSO4 19.26g/L for the optimal production of cartotenoids that was 1208 �慊/L. In addtion, NaCl, MgCl2, MgSO4, and NaHCO3 were also effective on cell growth by PBD method. From the steepest ascent analysis, the better combination of inorganic salts were NaCl 117, MgCl2 7.735, MgSO4 11.932, and NaHCO3 0.222 g/L for the cell growth rate (μm, 1.04±0.04 OD520nmh-1) and maximum cell concentration (9.29±0.05 OD520nm). Using different solvents to extract cartotenoids, the highest yield was obtained by acetone extraction. Meanwhile, the time needed for the acetone-extraction of cartotenoid was less than 10 min. as the solid-solvent ratio ≦ 0.5. Thee major carotenoids were separated and identified by silica gel chomatography, TLC, HPLC, and molecular spectrum.