Green fluorescent protein-expressing Escherichia coli as a model system for investigating the antimicrobial activities of silver nanoparticles
Green fluorescent protein-expressing Escherichia coli as a model system for investigating the antimicrobial activities of silver nanoparticles
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DOI：
10.1021/la060661v
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发表时间：
2006-10-24
期刊：
影响因子：
3.9
通讯作者：
Chattopadhyay, Arun
中科院分区：
文献类型：
--
作者：
Gogoi, Sonit Kumar;Gopinath, P.;Chattopadhyay, Arun
使用表达绿色荧光蛋白 (GFP) 的重组大肠杆菌 (E. coli) 细菌作为模型系统来研究银纳米粒子 (NP) 的抗菌活性。开发了一种在细菌生长培养基中使用硼氢化钠原位合成银纳米颗粒的便捷方法，以生产用于研究的预制纳米颗粒。荧光光谱和显微技术可以快速检测细菌生长随时间的变化以及银纳米颗粒存在下的荧光特性。此外，还进行了 X 射线衍射、紫外可见光谱和透射电子显微镜测量，以了解 Ag NP 对细菌的影响。我们的观察表明，超过一定浓度的银纳米粒子不仅具有杀菌作用，而且与未经处理的细菌相比，经处理的细菌的大小也减少了。培养基中 GFP 荧光增加表明经 Ag NP 处理的细菌发生细胞裂解。通过分光光度分析检测体外 DNA-Ag NP 相互作用。然而，电泳研究表明 Ag NP 对 DNA 或蛋白质谱没有直接影响。
Recombinant Escherichia coli (E. coli) bacteria expressing green fluorescent protein (GFP) was used as a model system to investigate the antimicrobial activities of Ag nanoparticles (NPs). A convenient in situ method of Ag NP synthesis using sodium borohydride, in the bacterial growth medium, was developed to produce preformed NPs for the study. Fluorescence spectroscopic and microscopic techniques allowed rapid detection of time-dependent changes in bacterial growth as well as fluorescence characteristics in the presence of Ag NPs. In addition, X-ray diffraction, UV-vis spectroscopic, and transmission electron microscopic measurements were carried out to understand the effect of Ag NPs on the bacteria. Our observations indicated that Ag NPs, above a certain concentration, not only were bactericidal but also were found to reduce the sizes of treated bacteria in comparison to untreated ones. Cell lysis of Ag NP-treated bacteria was suggested by the increased GFP fluorescence obtained in the medium. In Vitro DNA-Ag NP interaction was detected by spectrophotometric analysis. However, electrophoresis studies indicated no direct effect of Ag NPs on DNA or protein profiles.