ABSTRACT

Silver nanoparticles (AgNPs) have been exploited for their broad-spectrum antibacterial effects and their vast applications, which are generating interest of researchers towards green synthesis of AgNPs. In this paper, we describe a novel biosynthesis of AgNPs employing secondary metabolites of Bacillus subtilis (SDUM301120). The mean particle diameter of AgNPs was calculated by the high-resolution transmission electron microscope (HRTEM). HRTEM analysis revealed the particle was spherical and distributed in the range of 2–26 nm. Crystal nature of the nanoparticles in the face-centered cubic structure was confirmed by the peaks in the X-ray diffraction pattern corresponding to (111), (200), (220), and (311) planes. The formation of the reduced AgNPs was monitored by UV–VIS spectrophotometer analysis which displayed a peak in the region of 430–460 nm. We investigated the antibacterial activity of AgNPs against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, Vibrio Parahaemolyticus ATCC 17802^T, and Acinetobacter baumanni ATCC 19606^T. The results show that AgNPs with enhanced antibacterial properties have significant antimicrobial effects compared with pure AgNPs, antibacterial substances (lipopeptide), and the mixture of lipopeptide and pure AgNPs. The bacteriostatic experiments compared with antibiotics showed that the obtained AgNPs had a promising future in the bacterial infections.

摘要

银纳米颗粒（AgNPs）具有广谱抗菌作用和广泛应用，已引起研究人员对AgNPs绿色合成的兴趣。在本文中，我们描述了一种新型的利用枯草芽孢杆菌的次级代谢产物合成AgNPs的方法。（SDUM301120）。AgNPs的平均粒径是通过高分辨率透射电子显微镜（HRTEM）计算的。HRTEM分析显示该颗粒为球形，分布范围为2–26 nm。通过对应于（111），（200），（220）和（311）平面的X射线衍射图谱中的峰证实了面心立方结构中的纳米颗粒的晶体性质。通过UV-VIS分光光度计分析监测还原的AgNP的形成，该分光光度计在430-460 nm区域显示一个峰。我们调查了AgNPs对大肠杆菌ATCC 25922，金黄色葡萄球菌ATCC 29213，副溶血弧菌ATCC 17802 ^T和的抗菌活性。鲍曼不动动杆菌ATCC 19606 ^Ť。结果表明，与纯AgNPs，抗菌物质（脂肽）以及脂肽和纯AgNPs的混合物相比，具有增强抗菌性能的AgNPs具有显着的抗菌作用。与抗生素相比的抑菌实验表明，所获得的AgNPs在细菌感染中具有广阔的前景。