期刊
ENVIRONMENTAL SCIENCE & TECHNOLOGY
卷 48, 期 1, 页码 316-322出版社
AMER CHEMICAL SOC
DOI: 10.1021/es403796x
关键词
-
资金
- National Science Foundation of China [21237002, 21225729]
Whereas the antimicrobial mechanisms of silver have been extensively studied and exploited for numerous applications, little is known about the associated bacterial adaptation and defense mechanisms that could hinder disinfection efficacy or mitigate unintended impacts to microbial ecosystem services associated with silver release to the environment. Here, we demonstrate that extracellular polymeric substances (EPS) produced by bacteria constitute a permeability barrier with reducing constituents that mitigate the antibacterial activity of silver ions (Ag+). Specifically, manipulation of EPS in Escherichia coli suspensions (e.g., removal of EPS attached to cells by sonication/centrifugation or addition of EPS at 200 mg L-1) demonstrated its critical role in hindering intracellular silver penetration and enhancing cell growth in the presence of Ag+ (up to 0.19 mg L-1). High-resolution transmission electron microscopy (HRTEM) combined with Xray photoelectron spectroscopy (XPS) and energy-dispersive spectrometry (EDS) analyses showed that Ag+ was reduced to silver nanoparticles (AgNPs; 10-30 nm in diameter) that were immobilized within the EPS matrix. Fourier transform infrared (FTIR) and C-13 nuclear magnetic resonance (NMR) spectra suggest that Ag+ reduction to AgNPs by the hemiacetal groups of sugars in EPS contributed to immobilization. Accordingly, the amount and composition of EPS produced have important implications on the bactericidal efficacy and potential environmental. impacts of Ag+.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据