Document Details
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Document Type |
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Thesis |
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Document Title |
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STUDY OF BIOFILM FORMATION AND HEAVY METAL RESISTANCE OF SOME BACTERIAL STRAINS IN SAUDI ARABIA دراسة المقدرة على تكوين الاغشية الحيوية المقاومة للمعادن الثقيلة في بعض السلالات البكتيرية في المملكة العربية السعودية |
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Subject |
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Faculty of Sciences |
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Document Language |
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Arabic |
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Abstract |
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Heavy metals found in nature and the excessive accumulations of heavy metals have an impact on humans and animals. Heavy metal toxicity can lower energy levels and damage the functioning of the brain, lungs, kidney and other essential organs. Cadmium and lead considered being toxic to organisms in a particular concentration. Patients with renal failure mainily due to drink contamination water with cadmium and lead. Biofilm has produced by microbes and have been found to be suitable for the remediation of pollutants. This study aimed to isolate and investigate the ability of bacterial isolates to produce a biofilm that can resist heavy metals (cadmium chloride (CdCl2) and lead nitrate Pb (NO3)2. Bacterial isolates were obtained from soil sample located at different areas from Saudi Arabia (Makkah, Taif and Jeddah). Fifty isolates have been tested for formation of biofilm by two methods. First method using Congo Red Agar (CRA) and Second using Tissue Culture Plate (TCP) method .Results revealed that 3 out of 50 isolates showed high biofilm formation. The three isolates (A2, ST and PS) that form strong biofilm were screened primary on nutrient agar plate contain 7ppm concentration of CdCl2 and Pb (NO3)2. Results indicated that all three (A2, ST and PS) isolates were resistance. The maximum tolerance concentration (MTC) of three isolates (A2, ST and PS) studied on nutrient agar plate supplemented with different concentrations ranged from (7, 10, 20, 50, 100, 120, 150, 200, 250 and 300 ppm) and (7, 20, 50,100, 150,200, 250,300,350,400,450,500 and 550) for CdCl2 and Pb (NO3)2 respectively. Results indicated that MTC values of Pb (NO3)2 were up to (450, 350 and 500 ppm) for ST, A2 and PS isolates respectively. While in CdCl2 the MTC were 150, 120 and 250 ppm) for ST, A2 and PS isolates respectively. The three isolates were studied the effect of CdCl2 and Pb (NO3)2 on bacterial growth using spectrophotometer. Results indicated that all three isolates (A2, ST and PS) growth decreased with the increase in concentration of Pb (NO3)2 and CdCl2. These isolates (A2, ST and PS) were identified by biochemical and 16S rRNA gene. The results indicated that isolates identified as B. cereus A2, B. cereus ST and P.aeruginosa PS. Plasmid curing was studied using elevated temperature method, results showed that all cured B. cereus A2 and P. aeruginosa PS colonies were resistance to 7ppm of CdCl2 and Pb (NO3)2 while B. cereus ST showed different pattern of resistance after curing. B. cereus ST selected for test removal Pb (NO3)2 and CdCl2 using inductively coupled plasma optical emission spectrometry (ICP-OES). Using ICP-OES showed removal lead up to 93% while in cadmium to 49 %. Antimicrobial susceptibilities patterns of identified bacteria were determined. All tested isolated strains showed resistance against to 3 or more antibiotics. In consolation B. cereus A2, B. cereus ST and P. aeruginosa PS strains were isolated from soil samples showed highest biofilm formation which considered important factor for heavy metals resistance. The biofilm represent a very renewable, promising, cost-effective and easy biotechnology for treatment of wide range contaminated effluents. |
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Supervisor |
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Dr. Ola Ibrahim El-Hamshary |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1439 AH
2018 AD |
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Co-Supervisor |
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Dr. Rania Marwan Makki |
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Added Date |
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Tuesday, June 5, 2018 |
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Researchers
| زينة محمد المرحبي | Almarhabi, Zainah Mohammed | Researcher | Master | |
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