Abd El-Ghany Mohamed N, Hamdi Salwa A, Korany Shereen M, Elbaz Reham M, Emam Ahmed N, Farahat Mohamed G
Botany and Microbiology Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
Zoology Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
Microorganisms. 2023 Apr 12;11(4):1006. doi: 10.3390/microorganisms11041006.
The current investigation addressed the green synthesis of silver nanoparticles (AgNPs) using newly isolated silver-resistant rare actinomycetes, SNPRA1 and SNPRA2, and investigated their impact on the mycotoxigenic fungi ATCC 11498 and ATCC 60532. The formation of AgNPs was evidenced by the reaction's color change to brownish and the appearance of the characteristic surface plasmon resonance. The transmission electron microscopy of biogenic AgNPs produced by SNPRA1 and SNPRA2 (designated Gn-AgNPs and La-AgNPs, respectively) revealed the generation of monodispersed spherical nanoparticles with average sizes of 8.48 ± 1.72 nm and 9.67 ± 2.64 nm, respectively. Furthermore, the XRD patterns reflected their crystallinity and the FTIR spectra demonstrated the presence of proteins as capping agents. Both bioinspired AgNPs exhibited a remarkable inhibitory effect on the conidial germination of the investigated mycotoxigenic fungi. The bioinspired AgNPs caused an increase in DNA and protein leakage, suggesting the disruption of membrane permeability and integrity. Interestingly, the biogenic AgNPs completely inhibited the production of total aflatoxins and ochratoxin A at concentrations less than 8 μg/mL. At the same time, cytotoxicity investigations revealed the low toxicity of the biogenic AgNPs against the human skin fibroblast (HSF) cell line. Both biogenic AgNPs exhibited feasible biocompatibility with HSF cells at concentrations up to 10 μg/mL and their IC values were 31.78 and 25.83 μg/mL for Gn-AgNPs and La-AgNPs, respectively. The present work sheds light on the antifungal prospect of the biogenic AgNPs produced by rare actinomycetes against mycotoxigenic fungi as promising candidates to combat mycotoxin formation in food chains at nontoxic doses.
本研究利用新分离出的耐银稀有放线菌SNPRA1和SNPRA2进行了银纳米颗粒（AgNPs）的绿色合成，并研究了它们对产毒真菌ATCC 11498和ATCC 60532的影响。反应颜色变为棕色以及特征性表面等离子体共振的出现证明了AgNPs的形成。由SNPRA1和SNPRA2产生的生物源AgNPs（分别命名为Gn-AgNPs和La-AgNPs）的透射电子显微镜显示，生成了平均尺寸分别为8.48±1.72 nm和9.67±2.64 nm的单分散球形纳米颗粒。此外，XRD图谱反映了它们的结晶度，FTIR光谱证明了存在作为封端剂的蛋白质。两种生物启发的AgNPs对所研究的产毒真菌的分生孢子萌发均表现出显著的抑制作用。生物启发的AgNPs导致DNA和蛋白质泄漏增加，表明膜通透性和完整性受到破坏。有趣的是，生物源AgNPs在浓度低于8μg/mL时完全抑制了总黄曲霉毒素和赭曲霉毒素A的产生。同时，细胞毒性研究表明生物源AgNPs对人皮肤成纤维细胞（HSF）细胞系的毒性较低。两种生物源AgNPs在浓度高达10μg/mL时均表现出与HSF细胞可行的生物相容性，Gn-AgNPs和La-AgNPs的IC值分别为31.78和25.83μg/mL。本研究揭示了稀有放线菌产生的生物源AgNPs对产毒真菌的抗真菌前景，有望成为以无毒剂量对抗食物链中霉菌毒素形成的候选物。
