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Document Type |
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Thesis |
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Document Title |
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THE ANTIOXIDANT ACTIVITY OF SOME ALGAE AND THEIR ASSOCIATED BACTERIA FROM THE RED SEA OF SAUDI ARABIA النشاطات المضادة للاكسدة لبعض الطحالب و البكتريا المصاحبة لها من البحر الاحمر بالمملكة العربية السعودية |
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Subject |
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faculty of science |
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Document Language |
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Arabic |
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Abstract |
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The Red Sea is a potential source of affordable and abundant natural products with great biological impacts. Seven algae and their associated bacteria have been studied for antioxidant activity. Algae-associated bacteria field still new, up to our knowledge this study could be the first of its kind in Saudi Arabia. The aim of investigation was examined the antioxidant activity of algae methanolic extracts. In addition, isolation and identification the associated bacteria, evaluation the antioxidant activity of the algal associated bacteria ethylacetate extracts. And phytochemical analysis of both extracts. The bacterial identification determined by 16S rRNA gene sequencing. The extracts were examined by 2,2-diphenyl-1-picrylhydrazyl and Ferric reducing antioxidant power (FRAP) methods as well as phytochemical content of these extracts. Extracts of Halimeda opuntia was the most active as free radical scavenger with EC50= (230.4 ± µg/ml) while the lowest was Cystoseira myrica with EC50= (650.7 ± 0.06µg/ml). FRAP values were the highest in brown algae followed by green and red which were nearly equivalent. Conversely, the identification was belonging to 6 families, Alteromonadaceae, Bacillaceae, Lactobacillaceae, Pseudomonadacae, Rhodobacteraceae, and Vibrionaceae. 17 isolates were identified, Lactobacillus plantarum showed the highest free radical scavenging with EC50= 17.7 µg/ml similar to synthetic antioxidant Butylated Hydroxytoluene (BHT) EC50= 18.7 µg/ml. While, Lysinibacillus fusiformis., Bacillus niacini and Vibrio parahaemolyticus showed lower activity about 60 ≥%. FRAP value of Lactobacillus extract was 2.00 mM ferric equivalent /mg of extract that close to BHT 2.5 mM FE/mg. While Vibrio harveyi, Bacillus niacini and Alteromonas australica showed over 0.021 mM FE/mg. The phytochemical analysis revealed the presence of secondary metabolites such as steroids and flavonoids in all tested extracts. The Red Sea algae are rich of new sources of antioxidant which could be used in food supplements and cosmetics. Further investigations are suggested to determine the active compounds. |
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Supervisor |
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Dr. Ebtihaj Jamaluddin Jambi |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1441 AH
2020 AD |
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Co-Supervisor |
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Dr. Sawsan Abdulaziz Rahimuddin |
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Added Date |
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Thursday, February 27, 2020 |
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Researchers
| دعاء خالد باغر | Baker, Doaa Khaled | Researcher | Master | |
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