الفهرس 
Aim of the workOnly 14 pages are availabe for public view
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Abstract
Eight marine microalgae species namely (Chlorella sorokiniana, Chlorella salina, Dunaliella salina, Amphora marina and Phaeodactylum tricornutum were selected to test their potentialities for production of polyunsaturated fatty acids (PUFAs). The screening strategy for the production of PUFAs in this study was GC/MS analysis. The results indicated that diatoms followed by green microalgae were the potential producers of PUFAs. Among the tested producers, Phaeodactylum tricornutum and Amphora marina found to be the hightest potential algae to produce PUFAs relatively high levels of EPA and ARA in particular. A Plackett–Burman statistical design of experiments was applied to screen the effect of different factors including Ca(NO3)2.4H2O, K2HPO4.3H2O, MgSO4.7H2O, Na2SiO3.9H2O, Na2CO3, H3BO3, MnCl2.4H2O, CuSO4.5H2O, HMoO4, ZnCl2, CoCl2.6H2O, FeCl3.6H2O, Na2EDTA.2H2O, Spirulina filtrate, Na2SeO3.5H2O, AlCl3 and glycerol as components of a production medium. As an important step in the process development of the microbial PUFA production, the culture conditions were optimized using a response surface methodology exploring the significant effect of temperature, light and the interaction between them on the EPA production. This optimization strategy led to a significant increase in the amount of EPA produced by Phaeodactylum tricornutum, where the amount of EPA increased from 1.6 mg/g biomass (1.69 mg/l representing 18.88 % of the total fatty acids) to 78.79 mg/g (24.661 mg/l representing 22.34 % of the total fatty acids) and the amount of DHA increased from 0.14 mg/g biomass (0.15 mg/l representing 1.6 % of the total fatty acids) to 62.187 mg/g (14.92 mg/l representing 11.98 % of the total fatty acids). ARA yield of Amphora marina increased when grown in the optimized conditions (85.14 mg/g) compared to that of control medium (0.95 mg/g). Also ARA concentration increased in the optimized conditions (115.62) compared to that of control medium (0.266 mg/L).