الفهرس 
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Abstract
Due to the increased demand to silver nano particles, its green synthesis becomes an important interest. During our study, different types of filamentous fungi were used for studying the biosynthesis of silver nanoparticles as a natural factory. Therefore, silver nanoparticles of different densities were investigated by different characterized method that recorded absorbance at 24 h for Aspergillus niger at (420nm), A. flavus at 450 nm, A. terrus 400 nm ,A. fumigates at 420nm and Fusarium oxysporum at 458nm using UV-visible spectrophotometer. While, the best size of silver nanopaticles are shown in colloidal solution had a diameter of approximately (11, 13, 23, 33 and 36 nm) which produced by Aspergillus niger, Fusarium oxysporum, A.candidus, A. flavus and A.fumigatus respectively.TEM shown different shapes of silver nanoparticles as spherical, oval and triangle shape without any aggregation at ranged from (6 to 14 nm) as observed in (A. niger, A. fumigatus and F.oxysporum) respectively. The nanoparticles were well separated with best size in case of (A. niger and A. fumigatus). FTIR, improved the presence of Amine and Amide I, II and carbonyl bound at (1643.2 cm_1 (1), 1604.7cm_1 (2) ,1801.4 cm_1 ,3994.5 cm_1 and 3201.6 cm_1 ) in nanosilver by produced fungi. As well as, its negative charge shown higher stability beak at (- 29.6mv) by zeta potential for A.niger. In addition, the metabolites of A.niger filtrate revealed the highest concentration of protein at (3.133± 0.371mg). The reaction mixture was successfully optimized to increase the yield of nanoparticles production. The optimum conditions were (AgNO3, 1-2 mM), presence of electron donor (glucose), at alkalinic PH 9 and temperature at 300 c. Whereas, the absorbance of nanosilver particles increased after optimization compared with before optimization by (1.4). Hence, silver nanoparticles production by this fungus were revealed through the presence of amino acid function group that carrying negative charge with single peak and higher stability. In addition, the presence of protein in metabolites of Asperigillus niger. So, the reduction of metal ions and stabilization of the silver nano particles was confirmed to occur by an enzymatic process that revealed the stability of nano silver particles at 420 nm until two months. Our results revealed that silver nanoparticles exhibited good antifungal activity against Asperigillus. fumigatus and Candida albicans even at low concentration (5 Mg/ml). In addition, its antibacterial against E.coli and Staphlcoccus aurus at (6Mg/ml).
Keywords: Ag-NPs, AgNo3, Different filamentous fungi. Optimization factors and antimicrobial activity.