University of Guilan Caspian Journal of Environmental Sciences 1735-3033 20 4 2022 10 01 Efficiency of biologically and locally manufactured silver nanoparticles from Aspergillus niger in preventing Aspergillus flavus to produce aflatoxin B1 on the stored maize grains 765 773 5760 10.22124/cjes.2022.5760 EN Abrar A. Haider Plant protection Department, College of Agricultural Engineering Sciences, University of Baghdad, Iraq Halima Z. Hussein Plant protection Department, College of Agricultural Engineering Sciences, University of Baghdad, Iraq Journal Article 2022 08 28 This study was conducted in the mycotoxins laboratory, College of Agricultural Engineering Sciences, University of Baghdad, Iraq to evaluate the efficiency of silver nanoparticles manufactured locally and biologically by <em>Aspergillus niger</em> in preventing <em>A</em>. <em>flavus</em> to produce aflatoxin B₁ (AFB₁). The results of laboratory isolation showed that the companion of fungi genera were <em>Aspergillus </em>spp., <em>Fusarium </em>spp., <em>Penicillum </em>spp. and <em>Rhizopus </em>spp. at rates of 5.66, 14.91, 21.18 and 38.86% respectively. The highest frequency of <em>A</em>. <em>flavus</em> was 19.32%. The results of the TLC test showed that all isolates produced AFB₁ in varying rates (%), and the Baghdad / Al-Youssifia isolate was the most productive of AFB₁, since it has a largest spot area and most intense fluorescence under the chromatographic plate, hence given a symbolic name AFBY7. The results of HPLC showed that the toxin concentration in the AFBY7 isolate was 124.167 ppb. Also, the results showed the high efficiency of A. <em>niger</em> in the manufacture of silver nanoparticles, as the colour of solution changed from yellow to dark brown. On the other hand, the results of using locally and biologically manufactured silver nanoparticles in the storage experiment to prevent the fungus from producing toxin showed superiority of treatments (T) 0.4, 0.6 and 0.8 mg L^-1, since AFB₁ was 0.0 ppb compared to T_0.2 (3.990 ppb). In addition, the results showed the efficiency of locally and biologically manufactured silver nanoparticles used in reducing AFB₁ in the storage experiment of maize grains stored. So that, T_0.6 and T_0.8 were superior in reducing the AFB₁ to 0.0, compared to T_0.2 and T_0.4, leading AFB₁ to reach 10.230 and 5.180 ppb respectively. https://cjes.guilan.ac.ir/article_5760_b3a937e9c0b3b69c0087ffbef897c272.pdf