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العنوان
BIOSYNTHESIS OF METALLIC NANOPARTICLES USING
FUNGI AND ITS APPLICATIONS /
المؤلف
Shrouk Salah El-deen Farah Mahmmoud
هيئة الاعداد
باحث / Shrouk Salah El-deen Farah Mahmmoud
مشرف / Yousseria M. Hassan Shetaia
مشرف / Refaat Ahmed El-Adly
مناقش / Eman M. Ahmed El-Taher
تاريخ النشر
2019.
عدد الصفحات
171p.:
اللغة
الفرنسية
الدرجة
ماجستير
التخصص
Molecular Biology
تاريخ الإجازة
1/1/2019
مكان الإجازة
جامعة عين شمس - كلية العلوم - المكروبيولوجي
الفهرس
Only 14 pages are availabe for public view

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Abstract

Summary
Nanotechnologyisthescienceandtechnologythatdealswiththemattersat nanoscale(10-9m)whichhavespecialproperties,completelydifferentfromtheir properties in thebulk counterparts. It is the science concernedwiththe production of nanomaterialsanddevicesthroughthedevelopmentofnaturalandsynthetic
Systems. Also, this technology involves fabricating, measuring, imaging and
manipulating matters, molecules or particles to improve the physical, chemical, physico-chemical and biological properties of these materials for different purposes and applications. Nanobiotechnology has many benefits like feasibility, can be scaled up, covering large areas by growth of mycelia, etc.
In the present study, eight fungal isolates (Paecilomyces variotii, Penicillium fellutanum, Penicillium ducluxii, Alternaria alternata, Aspergillus niger, Penicillium rugulosum, Aspergillus terreus and Penicillium variabile) were isolated from different soil samples in Egypt, using malt extract agar (MEA) and potato dextrose agar (PDA) media. These fungal isolates were purified and were screened for the biosynthesis of six different metallic nanoparticles (Silver, copper, aluminum, zinc, chromium and iron).
Different NPs were biologically synthesized using fungi due to reduction of different metal salts’ solutions with the active metabolites produced by the eight fungal species at room temperature. Firstly, the biosynthesis of these metallic mycosynthesized nanoparticles can be detected through the observation of the color changing of filterates before and after the addition of metal solutions. The characterization of the biosynthesized NPs can be carried out using UV-visible spectroscopy and TEM (Transmission electron microscopy).
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Summary
In this study, the shape of mycosynthesized was ranged from spherical to polydisperse with an average size of (5-50 nm), and the majority of the particles were less than 20 nm.
In the present study, the best fungal isolates that can achieve efficiently the process of biosynthesis of metallic nanoparticles include; Alternaria alternata for biosynthesis of AgNPs, Penicillium duclauxii for biosynthesis of Cu-NPs and Aspergillus nigerforAlNPs.
The optimum parameters that can be contributed in the ideal production of different biosynthesized metallic nanoparticles and were as follow; agitation speed of 150 rpm, a temperature of 28 °C, a substrate concentration of 10 mM, size of inoculum was 10 g, a pH of 6.0. Glucose was the optimum carbon source for the biosynthesis of AgNPs, fructose was the optimum carbon source for the biosynthesis of Cu-NPs, 3g/l of NaNO3 was an optimum concentration of the used nitrogen source, and MEA was the optimum medium for the biosynthesis of silver, copper and aluminum nanoparticles using Alt. alternata, P. ducluxii and A. niger, respectively.
Further characterization of these three selected mycosynthesized nanoparticles (AgNPs, Cu-NPs and AlNPs) was carried out using DLS(Dynamic light scattering) with Zeta potential to confirm the stability of myco-synthesized NPs ; in case of freshly prepared AgNPs, the Zeta potential was -21.7mv, while, it was -18.3mv after 2 months of biosynthesis. Similarly, in case of freshly prepared Cu-NPs, the Zeta potential was -24.6mv, while that biosynthesized since 2 months, the Zeta potential was -21.5mv. However, the zeta potential of AlNPs was -27.5mv and after 2 months of biosynthesis, it was -25.5mv.
The prepared nanoparticles were analyzed by using XRD. There were four well- defined characteristic peaks at 38.27 o ,44.55o, 64.29 o and 77.8o. The relatively sharp peaks confirmed the crystalline nature of AgNPs. The XRD patterns of CuO- NPs showed four distinct peaks at 31.60 o, 35.25 o, 38.39 o and 48.58o, which well indexed to the cubic CuO.
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Summary
Furthermore, the XRD pattern showed that the aluminananoparticles were amorphous (not shown) due to their small particles in size with high surface area which is benefit when used as a support.
These three metallic nanoparticles were incorporated in different applications. First of all, we can used these NPs as antimicrobial agents against different bacterial (Staphylococcus aureus, Bacillus subtilis Pseudomonas aeruginosa &Escherichia coli) and fungal (Aspergillus niger, Penicillium italicum, Candida albicans &Geotricum candidum) pathogens, in comparison with standard drugs. We found that, the myco-synthesized NPs were showed weak antimicrobial activities against each of Bacillus subtilis, Staph. aureus, E. coli and A. niger in compared with the standard antibacterial and antifungal drugs and the minimal inhibitory concentrations were athighervalues.
Secondly, we used these myco-synthesized AgNPs, Cu-NPs and AlNPs to evaluate the anti-wear properties of the lithium lubricating grease with and without myco- synthesized NPs and we found a marked reduction of the wear loss in case of using NPs as nanoadditives in compared with blank. In this respect, the CuO-NPs showed the most effective reduction of wear rate as nano-additive or improver to reduce the friction and the wear behavior.
Finally, silver, copper and aluminum nanoparticles were used as photocatalyst to increase the photo degradation efficiency of P-nitrophenol (PNP) as an example of toxic aromatic compound. The photocatalytic degradation on Ag-Cu/Al catalyst was steadily increased from 54.3% to 70.8% in compared with Cu/Al catalyst after exposed to visible-light irradiation for 12 hrs.
The obtained results confirmed that, the myco-synthesized Ag, Cu and Al nanoparticles can offer a promising eco-friendly, cost effective and an alternative way to the chemical and synthetic methods, and could have wide applications in differentfields