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Document Type |
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Thesis |
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Document Title |
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HEAVY METAL-TOLERANT ACTINOMYCETES OCCURRING IN CAVE SOILS AND WALLS OF AL- SAMAN REGION, SAUDI ARABIA الأكتينوميستات المقاومه للمعادن الثقيلة المعزولة من تربة وجدران كهفوف منطقه الصمان, المملكة العربية السعوية. |
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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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Soil contamination with heavy metals become severe problems and cause several disorders in humans like anaemia, cancer, kidney failure, and Alzheimer’s. Using microorganisms to eliminate contamination of the environment is an efficient process. The aim of this study was to isolate actinomycetes with abilities to remove the harmful heavy metals. Different samples were collected from Mossy, Hotel and Reda caves which were located approximately 200 km of Riyadh region for actinomycetes isolation on starch nitrate agar medium. All isolates were screened for heavy metal resistance by adding different concentrations of copper (II) sulfate (10-90 mg/l) and nickel (II) chloride (10- 200 mg/l) to the medium separately to determine the minimum inhibitory concentration (MIC). MICs of a mixture of copper and nickel were determined for each strain. The most resistant actinomycetes were isolates NM5, NM16 and NM20 which were morphologically and physiologically characterized. Phylogenetic analysis by sequencing the 16S rRNA genes for the selected strains was performed. The isolates NM5, NM16 and NM20 were identified as Amycolatopsis sp. CA11, Streptomyces sp. YIM75782 and Amycolatopsis orientalis, respectively. The effect of copper and nickel concentration on growth of the isolates NM5, NM16, NM20 were determined by the dry weights which were reduced by increasing the tested metal concentration. The factors affecting heavy metal removal process such as temperature, pH, addition of yeast extract and incubation time were studied and removal percentage of copper and nickel was calculated after measuring the remaining concentration using Inductively couple plasma (ICPE-9000). It was found that after 5 days, the most removal activity for copper was 95% by Streptomyces sp. YIM75782 while it was 97% for nickel by the isolates Amycolatopsis sp. CA11 and Streptomyces sp. YIM75782. In conclusion; bacterial isolates from caves were resistant to some heavy metals, copper and nickel and can be used for removal activities. |
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Supervisor |
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Prof. Dr. Magda Mohamed Aly |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1440 AH
2019 AD |
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Co-Supervisor |
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Dr. Reda Hassan Amasha |
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Added Date |
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Monday, April 1, 2019 |
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Researchers
| نورة سعيد الزهراني | AlZahrani, Nourah Saeed | Researcher | Master | |
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