Alghuthaymi Mousa A, Abd-Elsalam Kamel A, Shami Ashwag, Said-Galive Ernest, Shtykova Eleonora V, Naumkin Alexander V
Biology Department, Science and Humanities College, Shaqra University, Alquwayiyah 11726, Saudi Arabia.
Plant Pathology Research Institute, Agricultural Research Center (ARC), Giza 12619, Egypt.
J Fungi (Basel). 2020 Apr 19;6(2):51. doi: 10.3390/jof6020051.
This work aimed to evaluate the fungicide activity of chitosan-silver nanocomposites (Ag-Chit-NCs) against from feed samples. The physicochemical properties of nanocomposites were characterized by X-ray fluorescence analysis (XRF), small-angle X-ray scattering (SAXS), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The morphological integrity of the nanohybrid was confirmed by electron transmission. By the data of RFA (X-ray fluorescent analysis), the contents of Ag in Ag-chitosan composite were 5.9 w/w%. The size distribution of the Ag nanoparticles incorporated in the chitosan matrix was investigated by SAXS. The main part of the size heterogeneity distribution in the chitosan matrix corresponds to the portion of small particles (3-4 nm). TEM analysis revealed a spherical morphology in the form of non-agglomerated caps, and 72% of the nanoparticles measured up to 4 nm. The minimum inhibitory concentration of NCs was evaluated in petri dishes. Three different concentrations were tested for antifungal activity against the mycotoxigenic strain. Changes in the mycelium structure of fungi by scanning electron microscopy (SEM) were observed to obtain information about the mode of action of Ag-Chit-NCs. It was shown that NC-Chit-NCs with sizes in the range from 4 to 10 nm have internalized sizes in cells, form agglomerates in the cytoplasm, and bind to cell organelles. Besides, their ability to influence protein and DNA fragmentation was examined in . SDS-PAGE explains the apparent cellular protein response to the presence of various Ag-Chit-NCs. The intensity of hyphal cell protein lines treated with Ag-Chit-NCs was very thin, indicating that high molecular weight proteins are largely prevented from entering the electrophoretic gel, which reflects cellular protein modification and possible damage caused by the binding of several protein fragments to Ag-Chit-NCs. The current results indicate that Ag-Chit-NCs <10 nm in size have significant antifungal activity against , the causative agent of blue mold-contaminated dairy cattle feed
本研究旨在评估壳聚糖 - 银纳米复合材料（Ag - Chit - NCs）对饲料样品中霉菌的杀菌活性。通过X射线荧光分析（XRF）、小角X射线散射（SAXS）、X射线光电子能谱（XPS）和透射电子显微镜（TEM）对纳米复合材料的物理化学性质进行了表征。通过电子透射确认了纳米杂化物的形态完整性。根据RFA（X射线荧光分析）数据，壳聚糖银复合材料中Ag的含量为5.9 w/w%。通过SAXS研究了壳聚糖基质中掺入的Ag纳米颗粒的尺寸分布。壳聚糖基质中尺寸异质性分布的主要部分对应于小颗粒（3 - 4 nm）部分。TEM分析显示为非团聚帽状的球形形态，72%的纳米颗粒尺寸达4 nm。在培养皿中评估了纳米复合材料的最小抑菌浓度。测试了三种不同浓度对产毒霉菌菌株的抗真菌活性。通过扫描电子显微镜（SEM）观察了霉菌菌丝体结构的变化，以获取有关Ag - Chit - NCs作用方式的信息。结果表明，尺寸在4至10 nm范围内的NC - Chit - NCs已内化到细胞中，在细胞质中形成团聚体，并与细胞器结合。此外，在……中检测了它们对蛋白质和DNA片段化的影响。SDS - PAGE解释了细胞对各种Ag - Chit - NCs存在的明显蛋白质反应。用Ag - Chit - NCs处理的霉菌菌丝细胞蛋白质条带强度非常低，表明高分子量蛋白质在很大程度上被阻止进入电泳凝胶，这反映了细胞蛋白质修饰以及几种蛋白质片段与Ag - Chit - NCs结合可能造成的损伤。目前的结果表明，尺寸小于10 nm的Ag - Chit - NCs对造成蓝霉污染奶牛饲料的病原菌具有显著的抗真菌活性
