Antibacterial activity and mechanism of silver nanoparticles on Escherichia coli
Antibacterial activity and mechanism of silver nanoparticles on Escherichia coli
复制标题
DOI：
10.1007/s00253-009-2159-5
复制
发表时间：
2010-01-01
影响因子：
5
通讯作者：
Chen, Yi-Ben
中科院分区：
文献类型：
--
作者：
Li, Wen-Ru;Xie, Xiao-Bao;Chen, Yi-Ben
通过对银纳米颗粒（SNPs）处理后大肠杆菌ATCC 8739的生长、通透性和形态学的分析，研究了SNPs对大肠杆菌ATCC 8739的抗菌活性及其作用机制。实验结果表明，10 μ g/ml的SNPs可以完全抑制10（7）cfu/ml的E.大肠杆菌细胞在液体Mueller-Hinton培养基中培养。同时，SNPs导致还原糖和蛋白质的渗漏，并诱导呼吸链淀粉酶进入失活状态，表明SNPs能够破坏细菌细胞膜的通透性。当E.大肠杆菌暴露于50 μ g/ml的SNPs后，透射电镜和扫描电镜观察到细菌细胞内有许多凹坑和缝隙，细胞膜破碎，表明细菌细胞受到严重破坏。在暴露于10 μ g/ml SNP后，膜囊泡溶解和分散，并且它们的膜组分从它们基于TEM观察的原始有序和紧密排列变得无序和分散。综合以上结果表明，SNPs可能会破坏细菌细胞膜的结构，抑制某些膜酶的活性，从而导致大肠杆菌的发生。大肠杆菌最终死亡。
The antibacterial activity and acting mechanism of silver nanoparticles (SNPs) on Escherichia coli ATCC 8739 were investigated in this study by analyzing the growth, permeability, and morphology of the bacterial cells following treatment with SNPs. The experimental results indicated 10 mu g/ml SNPs could completely inhibit the growth of 10(7) cfu/ml E. coli cells in liquid Mueller-Hinton medium. Meanwhile, SNPs resulted in the leakage of reducing sugars and proteins and induced the respiratory chain dehydrogenases into inactive state, suggesting that SNPs were able to destroy the permeability of the bacterial membranes. When the cells of E. coli were exposed to 50 mu g/ml SNPs, many pits and gaps were observed in bacterial cells by transmission electron microscopy and scanning electron microscopy, and the cell membrane was fragmentary, indicating the bacterial cells were damaged severely. After being exposed to 10 mu g/ml SNPs, the membrane vesicles were dissolved and dispersed, and their membrane components became disorganized and scattered from their original ordered and close arrangement based on TEM observation. In conclusion, the combined results suggested that SNPs may damage the structure of bacterial cell membrane and depress the activity of some membranous enzymes, which cause E. coli bacteria to die eventually.