-This study investigates the feasibility of β-carotene production from Dunaliella salina isolated from the Dead Sea employing a number of interdependent steps and focusing on the laboratory scale cultures. Then the produced β-Carotene was subjected to enzymatic oxidation using the enzyme 15,15' β-β carotene dioxygenase to produce tretinoin (vitamin A). The produced vitamin A was verified using proper analysis. Dunaliella salina was isolated from the Dead Sea and cultivated using a certain media until the cell count was 6 million cell/ml, then it was centrifuged and extracted using organic solvents and oils like jojoba oil and ethanol. The extracted β-carotene was subjected to enzymatic oxidation in a bioreactor under inert atmosphere of nitrogen. Freeze drying step was performed to obtain vitamin A as powder. The produced vitamin A powder was of a very high purity, and it has a very strong economic potentiality.Keywords: -β-Carotene, Cultivation, Dunaliella salina, Freeze Drying, Vitamin A.
INTRODUCTIONThe Dead Sea is called the salts sea, is a salt lake with 67 km long and (18) km width at the widest point. The Dead Sea has a density of (1.24) kg/l which makes swimming similar to floating. The Dead Sea was composed of two stratified layers of water that differed in temperatures, density, age and salinity. The mineral contact of the Dead Sea is very different from other ocean water, the exact composition of the Dead Sea water varies mainly with season, depth and temperature. Researches from Hebrew university found the Dead Sea to be teeming with type of alge called dunaliella [1].The dunaliella in turn nourished carotenoid containing (red pigmented) halobacter whose presence caused the color change [2].In recent decades, the Dead Sea has been rapidly shrinking because of diversion of incoming water from the Jordan River to the north. The southern end is fed by a canal maintained by the Dead Sea Works, a company that converts the sea's raw materials. From a depression of 395 m (1,296 ft) below sea level in 1970 it fell 22 m (72 ft) to 418 m (1,371 ft) below sea level in 2006, reaching a drop rate of 1 m (3 ft) per year. As the water level decreases, the characteristics of the Sea and surrounding region may substantially change. The water level is now -425 m. The Dead Sea level drop has been followed by a groundwater level drop, causing brines that used to occupy underground layers near the shoreline to be flushed out by freshwater. This is believed to be the cause of the recent appearance of large sinkholes along the western shore incoming freshwater dissolves salt layers, rapidly creating subsurface cavities that subsequently collapse to form these sinkholes. The dead sea climate offer year round sunny skies and dry air ,it has less than (50)mm mean annual rainfall and summer average temperature between (32c°) and (39c°) , winter average temperature range between (20c°) and (23c°) (Abusara et al, 2011).The region has weakened ultra violate radiation, particularly the UVB (erythrogenic rays), and an atm...
