الفهرس 
Aim of the workOnly 14 pages are availabe for public view
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Abstract
Although nanoparticles can be made using various
physicochemical methods that remains expensive and involves
the use of hazardous chemicals. Biological synthesis of
nanoparticles appears as a suitable process since it requires less
energy, is environmentally safe, emerges as an eco-friendly,
scalability, exciting approach, it has low manufacture costs of
scalability, and better nanoparticle stabilization, compared to
chemically synthesized nanoparticles.
This study illustrates simple, green synthesis of AgNPs in
vitro using cell lysate supernatant (CLS) of fungal species and
to investigate its potential antimicrobial, antiviral activities, and
cytotoxic effects against some tumor cell lines.
The production ability of silver nanoparticles was
investigated by the means of UV-V spectroscopy where
changing of the color of the culture filtrate from yellow to
brown, indicated the presence of extracellular silver
nanoprticles. In addition, electron microscopy (Transmission
and scanning electron microscopy) are used for characterization
of extracellular silver nanoparticles and Atomic absorption
spectroscopy, X-ray microanalysis and Transmission electron
microscopy were used for characterization of intracellular silver
nanoparticles.
The parameters controlling the biosynthesis process of
nanosilver including temperature, pH, time of incubation,
concentration of substrate and weight of biomass were fully
investigated.
The results revealed that,
The production of extracellular silver nanoparticles by
isolated fungi Penicillium citreonigrum, Penicillium
citreonigrum, Aspergillus niger and Penicillium
aurantiogriseum and Streptomyces albus is reported in this
study.
The biosynthesized nanoparticles exhibited typical plasmon
absorption maximum of silver nanoparticles (420nm). The
result of scanning electron microscope (SEM) and
transmission electron microscope (TEM) showed that the
spherical silver nanoparticles were found to have size
between 10 and 50 nm.
The fugal isolate Fusarium moniliforme and actinomycetes
isolate Streptomyces albus were reported in this study for
production of intracellular silver nanoparticles. X-ray pattern
revealed the crystalline nature of the silver nanoparticles.
Atomic absorption spectrophotometer measured the
remaining silver ions in the culture media, which indicated
the ability of isolates to uptake the silver ions and
biotransform it to nanoparticles. In addition, TEM showed
the presence of the silver nanoparticles inside the cells
microbial isolates.
AgNPs exhibited pronounced cytotoxic activity against
HepG2, HCT-116 and MCF-7 cell lines in vitro. By studying
the mode of action using inverted microscope and SEM it
was found that, AgNPs were very effective on the number
and on the cell contact which lead the cells to apoptosis
AgNPs exhibited promising cytoprotective efficacy towards
Herpes simplex type 2 virus. Also, AgNPs had no toxic effect
on the Vero cells (normal cells) compared with silver nitrate.
The mode of antiviral action of the silver nanparticles
indicated the best time to exert their effect on HSV-2 just
after the virus inoculation (at zero time) by high percentages.
Silver nanoparticles have broad spectrum antimicrobial
activity against Gram positive and negative bacteria and
pathogenic fungi.Studying the mode of action of the silver
nanoparticles on E. coli and P. notatum revealed that there
were a leakage of protein, lipid, glucose and LDH enzyme
from bacterial and fungal cells. There were extreme changes
in the morphological structure and in the number of growing
cells and also, there were damages in the treated cells
including cell wall, cell membrane and in cytoplasmic
organells of the cells.
In conclusions,
• The studies showed that the microbial susceptibility to
AgNPs is different for each microorganism.
• Penicillium citreonigrum and Streptomyces albus have
capacity to biosynthesize extracellular silver nanoparticles.
• Fusarium moniliforme and Streptomyces albus have capacity
to biosynthesize intracellular silver nanoparticles, which are
intracellularly accumulated.
• This property is present in whole cells and in free cell
extracts indicating that this process is probably enzymatically
mediated, due to the requirement of NADH as cofactor for
this biological transformation.
• In addition, AgNPs showed a promising result as
antimicrobial against pathogenic bacteria and fungi, antiviral
against Herpes simplex type 2 virus and antitumor substance
against the tumor cell lines such as HepG2, HCT-116 and
MCF-7 in vitro.
• Moreover, from these results the biological synthesized silver
nanoparticles from fungi and actinomycetes can be used in
different biological applications in different fields of science
including medicines, pharmaceutical industry, agriculture and
electronics.