Abdel-Hafez Sobhy I I, Nafady Nivien A, Abdel-Rahim Ismail R, Shaltout Abeer M, Daròs José-Antonio, Mohamed Mohamed A
Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut, 71516, Egypt.
Plant Pathology Research Institute, Agricultural Research Center, Giza, 12655, Egypt.
3 Biotech. 2016 Dec;6(2):199. doi: 10.1007/s13205-016-0515-6. Epub 2016 Sep 21.
Mycogenic synthesis of silver nanoparticles (AgNPs) was carried out in the present investigation using an aqueous extract of endophytic non-pathogenic Alternaria solani F10 (KT721914). The mycosynthesized AgNPs were characterized by means of spectroscopic and microscopic techniques. The surface plasmon resonance found at 430 nm confirmed the formation of stable AgNPs for several weeks at room temperature. Also, the results revealed the formation of spherical and monodispersed AgNPs with an average size of 14.8 ± 1.2 nm. The FT-IR spectrum suggested that the fungal extracellular proteins and secondary metabolites had the role in Ag reduction and AgNPs capping of which protein Ag nanoconjugates were formed. Furthermore, the mycosynthesized AgNPs exhibited potent antifungal activity against different pathogenic isolates of the same Alternaria solani fungus, the causal pathogen of tomato early blight disease. The antifungal efficiency of the AgNPs at 1, 5 and 10 ppm were evaluated for 8 days after incubation by measuring the inhibition rate of fungal radial growth. The results were further supported by investigating fungal hyphae morphology alteration by scanning and transmission electron microscopy. Treated fungal hyphae showed formation of pits and pores. Also, the mycosynthesized AgNPs were able to pass and distribute throughout the fungal cell area and interact with the cell components.
在本研究中，利用内生非致病性链格孢菌F10（KT721914）的水提取物进行了银纳米颗粒（AgNPs）的真菌合成。通过光谱和显微镜技术对真菌合成的AgNPs进行了表征。在430nm处发现的表面等离子体共振证实了在室温下稳定的AgNPs能够形成数周。此外，结果显示形成了平均尺寸为14.8±1.2nm的球形且单分散的AgNPs。傅里叶变换红外光谱表明，真菌细胞外蛋白质和次生代谢产物在Ag还原和AgNPs封端中起作用，由此形成了蛋白质Ag纳米共轭物。此外，真菌合成的AgNPs对番茄早疫病的致病病原菌——同一种链格孢菌的不同致病分离株表现出强大的抗真菌活性。通过测量真菌径向生长的抑制率，评估了1、5和10ppm浓度的AgNPs在培养8天后的抗真菌效率。通过扫描电子显微镜和透射电子显微镜研究真菌菌丝形态变化，进一步支持了这些结果。经处理的真菌菌丝出现了凹坑和孔隙。此外，真菌合成的AgNPs能够穿过并分布在整个真菌细胞区域，并与细胞成分相互作用。
