Department of Chemical Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran.
Department of Medical Nanotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
BMC Microbiol. 2022 Apr 11;22(1):97. doi: 10.1186/s12866-022-02490-5.
The use of bacteria to synthesize nanoparticles as an environment-friendly method has recently been considered by researchers. Bacteria residing in different mines have shown high potential in the synthesis of metal nanoparticles due to their compatibility with the environment. The aim of this study was to evaluate the ability of Zarshouran gold mine bacteria to synthesize silver nanoparticles and their antibacterial activity.
After isolation of mine bacteria and several screening steps, silver ion tolerant bacteria that were able to synthesize extracellular silver nanoparticles were isolated and the most suitable isolate was selected and sequenced. The characteristics, stability, and production efficiency of silver nanoparticles were evaluated using UV-vis spectrophotometry, DLS, TEM, FTIR, and X-ray diffraction analysis. Finally, the antibacterial effect of silver nanoparticles against pathogenic bacteria was investigated.
Among the eight silver-tolerant bacteria, isolate No. 6 had high antibacterial activity and high potential in the synthesis and stabilization of silver nanoparticles. Therefore, this isolate was selected for the next experiments. The results of 16S rDNA sequencing showed that this isolate is related to Bacillus pumilus. We registered in the NCBI Bank called ROM6 with access number MW440543. The DLS and TEM analysis showed that silver nanoparticles produced by this isolate were most spherical with a size of less than 25 nm and were stable for at least 180 days. The efficiency at concentrations less than 0.9 g/l silver nitrate was over 90% and the minimum inhibition concentration of nanoparticles was determined against S. aureus, E. coli, P. aeruginosa, and A. baumannii ranging from 1.4 to 5.6 µg/ml.
We found that the bacteria residing in the gold mine have a high capacity for the synthesis of spherical and high stable silver nanoparticles with a strong antibacterial effect.
利用细菌合成纳米颗粒作为一种环保的方法，最近受到了研究人员的关注。由于与环境的兼容性，不同矿山中存在的细菌在金属纳米颗粒的合成方面表现出了很高的潜力。本研究旨在评估扎尔舒兰金矿细菌合成银纳米颗粒的能力及其抗菌活性。
在分离出矿山细菌并经过多次筛选后，分离出能够合成胞外银纳米颗粒的耐银离子细菌，并选择最适宜的分离株进行测序。使用紫外可见分光光度法、DLS、TEM、FTIR 和 X 射线衍射分析来评估银纳米颗粒的特性、稳定性和生产效率。最后，研究了银纳米颗粒对致病菌的抗菌作用。
在 8 株耐银细菌中，菌株 6 具有较高的抗菌活性和较高的银合成及稳定潜力。因此，选择该菌株进行下一步实验。16S rDNA 测序结果表明，该菌株与解淀粉芽孢杆菌（Bacillus pumilus）有关。我们已将其在 NCBI 银行注册，登录名为 ROM6，登录号为 MW440543。DLS 和 TEM 分析表明，该菌株产生的银纳米颗粒呈最球形，尺寸小于 25nm，至少稳定 180 天。在低于 0.9g/l 硝酸银浓度下，效率超过 90%，纳米颗粒对金黄色葡萄球菌、大肠杆菌、铜绿假单胞菌和鲍曼不动杆菌的最小抑制浓度范围为 1.4 至 5.6μg/ml。
我们发现，金矿中存在的细菌具有很强的合成球形、高稳定性银纳米颗粒的能力，且具有很强的抗菌作用。
