creators_name: Ansari, Mohammad Azam
creators_name: Khan, Haris Manzoor
creators_name: Khan, Aijaz Ahmed
creators_name: Ahmad, Mohammad Kaleem
creators_name: Mahdi, Abbas Ali
creators_name: Pal, Ruchita
creators_name: Cameotra, Swaranjit Singh
type: article
datestamp: 2014-05-30 04:22:25
lastmod: 2014-05-30 04:22:25
metadata_visibility: show
title: Interaction of silver nanoparticles withEscherichia coliand their cell envelope biomolecules
ispublished: pub
subjects: QR
keywords: CLSM;HR-TEM;LPS;PE;ATR–FTIR
note: Copyright of this article belongs to Wiley.
abstract: be in the range of 11.25–22.5 µg ml−1. The growth kinetics curve shows that 25 µg ml−1 AgNPs strongly inhibits the bacterial growth. Confocal laser scanning electron microscopy (CLSM) shows that as the concentration of NPs increases, reduction in the number of cells was observed and at 50 µg ml−1 of NPs, 100% death was noticed. Scanning electron microscopy (SEM) shows cells were severely damaged with pits, multiple depressions, and indentation on cell surface and original rod shape has swollen into bigger size. High resolution-transmission electron microscopic (HR-TEM) micrograph shows that cells were severely ruptured. The damaged cells showed either localized or complete separation of the cell membrane. The NPs that anchor onto cell surface and penetrating the cells may cause membrane damage, which could result in cell lysis. The interaction of AgNPs to membrane biomolecules; lipopolysaccharide (LPS) and l-α-phosphatidyl-ethanolamine (PE) were investigated by attenuated total reflectance–fourier transform infrared (ATR–FTIR) spectroscopy. LPS and PE showed IR spectral changes after AgNPs exposure. The O-antigen part of LPS was responsible for interaction of NPs through hydrogen bonding. The phosphodiester bond of PE was broken by AgNPs, forming phosphate monoesters and resulting in the highly disordered alkyl chain. The AgNPs-induced structural changes in phospholipid may lead to the loss of amphiphilic properties, destruction of the membrane and cell leaking. The biomolecular changes in bacterial cell envelope revealed by ATR–FTIR provide a deeper understanding of cytotoxicity of AgNPs.
date: 2013
date_type: published
publication: Journal of Basic Microbiology
publisher: Wiley
id_number: doi:10.1002/jobm.201300457
refereed: TRUE
issn: 0233111X
official_url: http://onlinelibrary.wiley.com/doi/10.1002/jobm.201300457/abstract
citation:   Ansari, Mohammad Azam and Khan, Haris Manzoor and Khan, Aijaz Ahmed and Ahmad, Mohammad Kaleem and Mahdi, Abbas Ali and Pal, Ruchita and Cameotra, Swaranjit Singh  (2013) Interaction of silver nanoparticles withEscherichia coliand their cell envelope biomolecules.  Journal of Basic Microbiology.   ISSN 0233111X     
document_url: http://crdd.osdd.net/open/1512/1/swaranjit13.pdf