El-Baghdady Khaled Z, El-Shatoury Einas H, Abdullah Omnia M, Khalil Mostafa M H
Department of Microbiology, Faculty of Science, Ain Shams University , Cairo , Egypt.
Department of Chemistry, Faculty of Science, Ain Shams University , Cairo , Egypt.
Turk J Biol. 2018 Aug 9;42(4):319-321. doi: 10.3906/biy-1801-53. eCollection 2018.
A bacterial isolate capable of tolerating 30 mM silver nitrate (AgNO3) was recovered from soil contaminated with industrial waste. The isolate was identified by 16S rRNA as Enterobacter cloacae Ism26 (KP988024) and its capability to synthesize silver nanoparticles (AgNPs) was investigated. AgNPs were produced by mixing 1 mM AgNO3 solution with bacterial cell lysate under light conditions. The UV-Vis spectrum of the aqueous medium containing AgNPs exhibited a peak at 440 nm corresponding to the surface plasmon resonance of the AgNPs. The crystalline nature of the particles was confirmed by X-ray difractometer. High-resolution transmission electron microscopy revealed that the AgNPs were spherical and well dispersed and ranged in size from 7 to 25 nm. The average size range of the produced AgNPs was confirmed by dynamic light scattering. Fourier transform infrared spectroscopy revealed possible involvement of reductive groups on the surface of the nanoparticles. The biosynthesized AgNPs were stable for 6 months and inhibited both gram-positive and gram-negative bacteria. This work describes the exploitation of a low-cost biomaterial and an easy method for the synthesis of AgNPs with desirable and advantageous characteristics.
从受工业废物污染的土壤中分离出一株能够耐受30 mM硝酸银（AgNO3）的细菌。通过16S rRNA鉴定该分离株为阴沟肠杆菌Ism26（KP988024），并对其合成银纳米颗粒（AgNPs）的能力进行了研究。在光照条件下，将1 mM AgNO3溶液与细菌细胞裂解液混合制备AgNPs。含有AgNPs的水介质的紫外可见光谱在440 nm处出现一个峰，对应于AgNPs的表面等离子体共振。通过X射线衍射仪确认了颗粒的晶体性质。高分辨率透射电子显微镜显示，AgNPs呈球形且分散良好，尺寸范围为7至25 nm。通过动态光散射确定了所制备的AgNPs的平均尺寸范围。傅里叶变换红外光谱表明纳米颗粒表面的还原基团可能参与其中。生物合成的AgNPs在6个月内稳定，对革兰氏阳性菌和革兰氏阴性菌均有抑制作用。这项工作描述了一种低成本生物材料的开发以及一种合成具有理想和有利特性的AgNPs的简便方法。
