4932
DIAA ATTIA GAB-ALLAH MARREZ
RISK EVALUATION DURING PRODUCTION OF SOME FUNCTIONAL INGREDIENTS FROM ALGAE IN EGYPTIAN AQUATIC ECOSYSTEMS
Microalgae, risk evaluation, function ingredients, microcystin, cancer cell lines, natural toxins.
The aims of this work are production and risk evaluation of some functional ingredients from the dominants microalgae in Egyptian aquatic. These were achieved throughout the study of ingredients activity against pathogens and cancer cells. In addition to the assessment of the fuctional ingredients (amino acids, fatty acids, minerals and pigments) in Spirulina platensis as a model for the other species under study. Ninety eight species of phytoplankton from 4 different sites were identified to specify the dominant species. Six species were isolated and purified. Four of them (Oscillatoria brevis, O. princeps, Microcystis aeruginosa and Spirulina platensis) belonged to Cyanophyta and the other two (Chlorella vulgaris and Scenedesmus obliquus) belonged to Chlorophyta. Because of the ability to produce Microcystin, O. brevis and M. aeruginosa were excluded from the study. Diethyl ether extract (DEE) of C. vulgaris gave the best inhibition being between 11.5 and 23.2 mm inhibition zone against all tested bacteria and fungi. Regarding to anticancer activity of DEE, the highest effect at LC50 was observed against both of HepG2 and MCF7 cell lines. Two compounds were identified as Hydroxyphenophytin B and Hexadecanoic acid Methyl ester. DEE of S. obliquus had the highest antimicrobial activity recording between 8.7 and 19.5 mm inhibition zones against bacteria and fungi. Also, low concentrations had anticancer effect at LC50 notably with HCT116 and HepG2 cell lines. Same trend recorded with previous two species, was observed with O. princeps which showed also the best bioactivity recording between 7.3 and 20.7 mm inhibition zone against all tested bacteria and fungi. Also, high activity was detected against cancer cell lines at LC50 especially MCF7 and HepG2 cell lines. Similarly, DEE of S. platensis had the best inhibition effect recording between 8 and 27.3 mm inhibition zones against the tested bacteria and fungi. Also, low concentrations of DEE showed high reduction in HepG2 and HCT116 cells at LC50. Two pure compounds were identified as Hexadecanoic acid and 9- Octadecanoic acid methyl ester. S. platensis were cultivated in 4 different reported media in order to select the best medium for biomass production, pigments content and chemical composition. Modified BG-11 was chosen as the best mediumcultivated in open system as well as closed system. Risk assessment of Spirulina from both system was evaluated (heavy metals, microbial load, natural toxins). Contaminants in Spirulina from both systems was within permissible limits. The effect of substitution of soybean by Spirulina in rabbits diets on meat quality was studied. The substitution 60% was the best one regarding to rabbits meat quality.
2015
Ph.d
Cairo
Agriculture