Table 11.1 (continued)

Type of

NPs

Bacterial

strains/cells

Proposed mode of

action

Effect caused

Refs.

large-scale

generation of ROS

and hydroxyl

radicals

oxidative stress

Apoptosis

Uncoated

Ag, Au,

Nic, and Si

E. coli

Diffusion leads to

the production of

superoxide

(AgNPs), hydroxyl

radicals (au and

Ni), and singlet

oxygen (Si NPs)

Altered cell

membrane

permeability and

accumulation of

generated toxic

enmities resulted

in bactericidal

killing

Zhang et al. (2013)

Adsorption

ZnO

E. coli

Zinc ion

interaction with the

-SH protein groups

results in the

generation of ROS

Disorganization of

morphological

symmetry of cell

membrane

Disruption of

cellular functions

Dispersed cell

membranes

Leakage of intra/

intercellular

proteins

Formation of

“pits”

Destroyed cellular

membrane

permeability

Depresses

enzymatic activity

of cellular

membrane

Apoptosis

Padmavathy and

Vijayaraghavan

(2011)

Inhibited translation and transcription

TiO2

E. coli and K

12 cells

NPs integrated

specifically with

G-C rich DNA

Compression of

bacterial DNA

Degeneration and

fragmentation of

nucleic acids

Diminished gene

expression

Iram et al. (2015)

and Zhukova

(2015)

Ag

E. coli,

S. aureus

Upregulation of

antioxidant

transporter and

efflux pumps

coding genes

Sterilization and

inhibited growth

Collapsed

antioxidant

potential

Nagy et al. (2011)

(continued)

162

A. Parmar and S. Sharma