Microbial Chemistry Department, Genetic Engineering and Biotechnology Research Division, National Research Centre, Dokki, Giza, Egypt.
Water Pollution Research Department, Environmental Research Division, Environmental Virology Lab, National Research Centre, Dokki, Giza, Egypt.
Prep Biochem Biotechnol. 2021;51(9):926-935. doi: 10.1080/10826068.2021.1875236. Epub 2021 Feb 2.
Silver nanoparticles (AgNPs) were synthesized using extracellular filtrates of some (Ls) strains under simple conditions. Ls synthesized AgNPs showed the optical absorption peaks at 388-412 nm as detected by UV-visible spectrophotometer. Transmission electron micrographs of bacterial synthesized AgNPs revealed that they were polycrystalline with spherical, hexagonal, cuboidal, rod and irregular shapes. The average diameter of the tested AgNPs were ranged from 14-21 nm and they were negatively charged as detected by DLS (-18.2 to -28.9). FTIR spectra showed the presence of nitrogenous biomolecules capping the synthesized AgNPs. The filtrates of tested Ls strains showed nitrate reductase activity (1.45-2.56 µmol/ml/min). Tested AgNPs showed bactericidal activity against Gram positive and Gram negative bacteria, fungicidal activity against yeast and filamentous fungi, and virucidal activity against rotavirus. In addition, it showed synergistic antimicrobial effect to cephradine and nizoarm against all tested microorganisms. Cytotoxicity test revealed the safety of the tested nanoparticles at tested concentrations.Finally, Ls strains represent microbial sources for ecofriendly, simple and economic biosynthesis of antimicrobial AgNPs. Also, this research may contribute to the medicinal chemistry and pharmaceutical industry for the development of new products used for the public health.
采用某些（Ls）菌株的胞外滤液在简单条件下合成了银纳米粒子（AgNPs）。紫外-可见分光光度计检测到 Ls 合成的 AgNPs 的光学吸收峰在 388-412nm 处。细菌合成的 AgNPs 的透射电镜照片显示，它们是多晶的，具有球形、六方、立方、棒状和不规则形状。测试的 AgNPs 的平均直径在 14-21nm 之间，通过 DLS 检测为带负电荷（-18.2 至-28.9）。傅里叶变换红外光谱显示存在氮生物分子覆盖合成的 AgNPs。测试的 Ls 菌株的滤液显示具有硝酸还原酶活性（1.45-2.56µmol/ml/min）。测试的 AgNPs 对革兰氏阳性菌和革兰氏阴性菌具有杀菌活性，对酵母和丝状真菌具有杀菌活性，对轮状病毒具有抗病毒活性。此外，它对所有测试的微生物对头孢拉定和尼佐阿莫具有协同抗菌作用。细胞毒性试验表明，在测试浓度下，测试的纳米颗粒是安全的。最后，Ls 菌株代表了微生物来源，用于生态友好、简单和经济的抗菌 AgNPs 的生物合成。此外，这项研究可能有助于药物化学和制药行业开发用于公共卫生的新产品。
