1. Science Fair Open Library | Inspiring the World of Science 2015 | Volume 1 | Issue 1 |NSTOL1114001006
Research Article
Characterization and antibacterial efficacy of silver nanoparticles biosynthe-
sized by the soil fungus Curvularia tuberculata
Tawfik M. Muhsin1
and Ahmad K. Hachim1
* Corresponding author: T.M. Muhsin, Department of Biology, College of Education for Pure Sciences, University of Basra, Basra, Iraq.
e-mail: tmuhsin2001@yahoo.com
Edited by: Prof. Mosaad A. Abdel-Wahhab, Food Toxicology & Contaminants Department, National Research Centre,Egypt.
e-mail: mosaad_abdelwahhab@yahoo.com
Open Access
Page 5
Abstract
Keywords: Antibacterial efficacy, Curvularia tuberculata, My-
cosynthesis, Pathogenic bacteria, Silver nanoparticles.
Introduction
Received: November 01, 2014 Accepted: January 30, 2015 Published: February 03, 2015
Materials and Methods
Biosynthesis of silver nanoparticles (AgNPs)
Fungal isolation and identification
The objective of this study was to biosynthesize silver nanopar-
ticles using the fungus Curvularia tuberculata isolated from soil
samples and to examine their efficacy against five strains of patho-
genic bacteria namely; Escherichia coli, Proteus mirabilis, Pseu-
domonas aeruginosa, Salmonella typhi and Staphylococcus aureus
using agar well diffusion technique. The efficacy of biosynthesized
silver nanoparticles in a combination with commercially used an-
tibiotic Gentamycin against the selected bacteria was examined.
The biosynthesized silver nanoparticles from filtrate were charac-
terized by UV-Vis spectrophotometer analysis, Fourier transform
infrared spectroscopy (FTIR) and scanning electron microscope
(SEM). UV-Vis spectrophotometer analysis showed a peak at 420
nm indicating the synthesis of silver nanoparticles, FTIR analy-
sis verified the detection of protein capping of silver nanoparti-
cles while SEM micrographs showed that the synthesized silver
nanoparticles are dispersed and mostly having spherical shape
within the size range between 10-50 nm. The mycosynthesized
silver nanoparticles (AgNPs) exhibited a varied growth inhibition
activity ranged between 12-25.5 mm diameter and 14.5-28 mm di-
ameter inhibition zone at 50 µl and 100 µl concentrations, respec-
tively, against the tested pathogenic bacterial strains. A remark-
able increase of bacterial growth inhibition zones (25.5-35.5 mm
diameter) was detected when a combination of silver nanoparticles
and Gentamycin was used as indicated by the increase in fold area
of antibacterial efficacy. The synthesized silver nanoparticles pro-
duced by the selected fungus C.tuberculata a promising to be used
as an antimicrobial agent in medical therapy due to their broad
spectrum efficacy against pathogenic bacteria.
Nanobiotechnology has been recently widely applied in multi-
disciplinary fields including agriculture, industry, environment
and medicine [14, 19]. The last decade has witnessed an increase
research interests focused on the biosynthesis of metal nanopar-
ticles from fungi and a new approach (Myconanotechnolgy) has
been lately emerged which involves the mycosynthesis of metal
nanoparticles using fungi as a natural sources and as bionanofac-
tories [14, 28]. Among the metals, silver nanoparticles are of great
importance particularly in medical therapy applications and such
aspect has encouraged the researchers to investigate fungi for their
capability to synthesize silver nanoparticles and to be used as an-
timicrobial agent [19, 24]. So far, noteworthy studies have been
conducted on mycosynthesis of silver nanoparticles by examin-
ing different species or strains of fungi [28]. Number of studies
reported that silver nanoparticles can produced by Fusarium oxy-
sporum [4], Penicillium sp. [30], Trichoderma asperellum [22],
Pestalotia sp. [8], Aspergillus niger [27], Aspergillus flavus [18]
and Nigropspora sphaerica [21]. Nonetheless, the silver nanopar-
ticles synthesized by fungi exhibit a good antimicrobial activity [8,
12] and a wide spectrum efficacy against bacteria and fungi [20]. A
continuation of research to explore more potent fungi for biosyn-
thesis of silver nanoparticles, the present study therefore, aimed
to examine the fungus Curvularia tuberculata for its capability for
synthesis of silver nanoparticles and to evaluate their antibacterial
efficacy against selected pathogenic bacteria.
The fungus Culvularia tuberculata Jain was isolated from subsur-
face soil samples collected from Basra (Southern Iraq) during the
year 2013. Fungal isolation was made by using soil samples dilution
method in Petri dishes containing an autoclaved Potato Dextrose
Agar (PDA) incubated at 25 °C for 5 days and axenic fungal cul-
tures of the growing colonies were made. The isolated fungus was
identified according to the taxonomic literature [5, 34]. The fungal
culture was prepared according to Karbasian et al. [13] as follows:
one disc (6 mm diameter) was cut from three days old fungal colo-
ny using a sterilized Cork borer and inoculated into 250 ml Erlen-
meyer flasks containing 100 ml of MGYP liquid medium (Malt ex-
tract, 3 g; Glucose, 10 g; Yeast, 3g; and Peptone 5g per 1L distilled
water) after being autoclaved at 121 °C for 15 min. The culture
flasks were incubated at 25 °C for 10 days; and the fungal mycelia
were harvested from the culture broth by filtration on Whatman
filter paper No.1 then centrifuged at 6000 rpm at 10 °C for 10 min.
The harvested mycelia were washed twice with sterilized distilled
water to remove the medium component from the mycelia biomass.
Ten g of the fungal mycelia (wet weight) was mixed with 100
ml deionized water in Erlenmeyer flask (250 ml) and agitated
in water bath at 120 rpm for 72 hrs at 25 °C. The fungal free-
cell filtrate (fcf) was filtered by Whatman filter paper No.1 then
the fcf was treated with 1 mM AgNO3
and incubated at room
temperature at dark condition. Flaks containing fungal fcf un-
treated with AgNO3
were used as control. Triplicate flasks
of the treated and untreated fungal filtrate were carried out.
1-Department of Biology, College of Education for Pure Sciences, University of Basra, Basra, Iraq
NanoSciTech Open Library

2. Cite this article:Muhsin T M, Hachim A K(2014).Characterization and antibacterial efficacy of silver nanoparticles biosynthesized by the soil fungus Curvularia tuberculata, NanoSciTech Open Lib, 1(1): 5-11.
Science Fair Open Library | Inspiring the World of Science 2015 | Volume 1 | Issue 1 |NSTOL1114001006Page 6
Characterization of biosynthesized silver nanoparticles
UV-Visible spectrophotometric assay
Fourier Transform Infrared (FTIR)
Scanning Electron Microscopic (SEM) analysis
Antibacterial efficacy of synthesized silver nanoparticles
Minimum inhibitory concentration (MIC) and minimal bacte-
ricidal concentration (MBC) assay
Antibacterial efficacy ofAgNPs combined with the commercial
Gentamycin
Assessment of increase in fold area of AgNPs combined with
Gentamycin
Results
3.1. Fungal culture and silver nanoparticles biosynthesis
The fungal free-cell filtrate treated with AgNO3
after being incu-
bated for 24 hrs was monitored using UV-Vis spectrophotometer
(APEL PD-303, Japan) at regular intervals. During the bioreduc-
tion process of Ag within the fungal free-cell filtrate solution, 0.1
ml of the filtrate was taken and diluted three times with deionized
water and centrifuged at 800 rpm for 5 min then the supernatant
was scanned using UV-Vis spectrophotometer at the wavelength of
300-900 nm. UV-Vis spectra were recorded at 24, 48, and 72 hrs at
a resolution of 1 nm. Untreated fcf was used as control.
After 72 hrs of incubation, the free-cell filtrate treated with AgNO3
was subjected to Fourier Transform Infrared (FTIR) (Shimadzu
UV-1700, Japan) analysis. After a complete reduction of aqueous
silver ions within the fungal filtrate, the filtrate was centrifuged at
4000 rpm for 15 min forming a pellet according to the described
method [27]. The supernatant was discarded and the precipitate
was dried to get the powder of silver nanoparticles. Characteriza-
tion of AgNPs was done by using FTIR at the range of 400-4000 /
cm at a resolution of 4 / cm.
Analysis of the fungal free-cell filtrate treated with AgNO3
was
performed using SEM (Netherland INSPECT S50). Thin films of
the filtrate samples were prepared on a carbon coated copper grids
by dropping an amount of the filtrate on the grid and the extra
solution was removed by a blotting paper then the films on the
grids were allowed to dry overnight at room temperature under a
sterilized condition. SEM images of the silver nanoparticles were
exposed at different magnifications.
The antibacterial efficacy of the synthesized silver nanoparticles
was examined using agar well diffusion assay method [25]. Five
strains of pathogenic bacteria including Escherichia coli, Proteus
mirabilis, Pseudomonas aeruginosa, Salmonella typhi and Staphy-
lococcus aureus were tested. Swabs from each bacterial culture
grown for 24 hrs were streaked on sterilized Muller-Hinton Agar
(MHA) in Petri dishes. Wells (5 mm diameter) were made in agar
plates using sterilized stainless steel Cork borer. The wells were
loaded with two concentrations (50 and 100 µl) of silver nanopar-
ticles solutions. The plates were incubated at 37 o
C for 24 hrs and
examined for the appearance of clear zones around the wells indi-
cating bacterial growth inhibition and the diameters of inhibition
zones were measured.
Minimum inhibitory concentration (MIC) of synthesized silver
nanoparticles was determined using the microtiter method accord-
ing to Qi et al. [26]. One hundred µl of AgNPs was transferred into
96- well microtiter plates containing one hundred µl of Mueller-
Hinton Broth (MHB). One hundred µl of the tested bacteria E.
coli (ATCC 25922) and S. aureus (NCTC 6571) was inoculated
into each well and incubated at 37 o
C for 24 hrs. After the incuba-
tion period a small amount of bacterial suspension was streaked on
MHA plates and incubated at the same conditions. The minimum
inhibitory concentration was determined and expressed as the low-
est concentration of AgNPs that inhibits the growth of bacteria.
While the minimum bactericidal concentration (MBC) was deter-
mined as the lowest concentration of AgNPs that kills the bacteria
and no growth on the agar medium was appeared.
Disc diffusion method was used to assay the antibacterial efficacy
of synthesized AgNPs combined with the commercial antibiotic
Gentamycin as described by Birla et al. [2]. A standard antibiotic
disc of Gentamycin was impregnated with 20 µl of freshly synthe-
sized AgNPs and placed onto the MHA medium inoculated with
each selected bacterial strain. Meantime, the antibacterial activ-
ity test for Gentamycin and for AgNPs was carried out as control.
Discs of Gentamycin and of AgNPs were separately placed on the
MHA medium inoculated with each tested bacteria. The plates
were incubated at 37 o
C for 24-48 hrs. After the incubation pe-
riod, the inhibition zones surrounding the bacterial growth for the
combination of AgNPs plus Gentamycin treatment and for control
plates were measured. Triplicates for each treatment were done.
The increase in fold area was assessed according to Birla et al. [2]
by calculating the mean surface area of the inhibition zone exhib-
ited by Gentamycin alone and in a combination with AgNPs. The
fold increase area was calculated by the following equation;
(A2
− B2
) / B2
,
where,
A refers to the inhibition zone diameter exhibited by activity of a
combination of Gentamycin and AgNPs and
B refers to the inhibition zone diameter exhibited by Gentamycin
alone.
The isolated fungus C. tuberculata grew rapidly on PDA medium
and covered the Petri plate within five days (Fig.1). The fungal
free-cell filtrate (fcf) obtained from the fungal cultures grown in
MGYP liquid medium after being treated with AgNO3
solution
changed from pale yellow color into dark brown color which indi-
cates the synthesis of silver nanoparticles (Fig.2).
Fig.1. Curvularia tuberculata culture grown on PDA medium (A) and micro-
scopic structures (B) showing fungal hyphae and conidia (40 X magnification)
Fig.2. Untreated fungal free-cell filtrate (A) and treated with 1mM silver nitrate
solution (B)

3. Cite this article:Muhsin T M, Hachim A K(2014).Characterization and antibacterial efficacy of silver nanoparticles biosynthesized by the soil fungus Curvularia tuberculata, NanoSciTech Open Lib, 1(1): 5-11.
Science Fair Open Library | Inspiring the World of Science 2015 | Volume 1 | Issue 1 |NSTOL1114001006Page 7
UV-Vis spectra of AgNPs
SEM analysis
FTIR spectroscopy
Antibacterial efficacy of synthesized silver nanoparticles
The UV-Vis spectra obtained from the fungal free-cell filtrates
treated with 1 mM AgNO3
solution showed significant variations
in spectra of silver nanoparticles synthesis at different intervals of
reaction (Fig. 3). The absorbance trend of the Ag-fcf monitored at
the range of 300-900 nm revealed an increase of absorbance with
increasing time of incubation at 420 nm. Highest spectrum of Ag-
NPs synthesis after 72 hrs of incubation was detected.
Fig.3. UV-Vis spectrum of fungal free-cell filtrate (fcf) containing silver nanopar-
ticles recorded at different exposure times
Images of SEM at different magnifications showed that the synthe-
sized silver nanoparticles are dispersed or aggregated and mostly
appeared as spherical shape and their size ranging between 10-50
nm (Fig.4).
Fig.4. SEM micrographs showing the silver nanoparticles in fungal free-cell filtrate
appeared as spherical shape (arrows) at magnification (13000X) with size range
between 10-50 nm
FTIR analysis of silver nanoparticles synthesized from the fungus
C. tuberculata showed the presence of peaks at 3404.11/cm and
3398.34/cm (Fig.5) refer to the bonding vibrations of the amide
(N-H group) of proteins while the bands at 1649 / cm and 1645 /cm
indicate the presence of C=O-NH group. FTIR-spectra showed the
absorbency bands of different chemical functional groups present
in the fungal free-cell filtrate of untreated and treated with AgNO3
(Table 1).
Fig.5. FTIR analysis of silver nanoparticles synthesis in fungal free-cell filtrates
before (a) and after (b) silver ions bioreduction
Table1. FTIR-spectra showed the absorbency bands of different
chemical functional groups in the fungal free-cell filtrate (fcf) un-
treated and treated with AgNO3
Functional groups Untreated fcf Treated fcf
N-H, OH 3404.11 /cm 3398.34 / cm
CH, CH2 2854.45 /cm 2854.45/ cm
C=O-OH 1741.60 /cm 1733.89 /cm
C=O-NH 1649.02 /cm 1654 /cm
C-O 1257.50 /cm 1261/cm
C-N 1309.02 /cm 1380.94 /cm
The mycosynthesized silver nanoparticles exhibited a pronounced
antibacterialefficacyagainstthetestedGrampositiveandGramneg-
ative bacteria (Fig.6). The bacterial growth inhibition zones ranged
(13-25.5 mm diameter) at 50 µl concentration of AgNPs while at
100 µl concentration the inhibition zone was ranged (14.5-28 mm
diameter) (Fig.7). The highest antibacterial efficacy of AgNPs at
50 µl /ml concentration was against P. aeruginosa (25.5 mm
diameter) and lowest against P. mirabilis (12 mm diameter).
The minimal inhibitory concentration (MIC) and minimal bac-
tericidal concentration (MBC) values against the two strains
of bacteria E. coli and S. aureus were very low (Table 2).

4. Cite this article:Muhsin T M, Hachim A K(2014).Characterization and antibacterial efficacy of silver nanoparticles biosynthesized by the soil fungus Curvularia tuberculata, NanoSciTech Open Lib, 1(1): 5-11.
Science Fair Open Library | Inspiring the World of Science 2015 | Volume 1 | Issue 1 |NSTOL1114001006Page 8
Fig.6. Appearance of inhibiton zones on agar plates using of silver nanoparticles
synthesized by the fungus Curvularia tuberculata against E. coli (A), S. aureus
(B), P. aeruginosa (C), S. Typhi (D) and P. mirabilis (E) at concentration 50 µl (1),
100 µl (2) of silver nanopartilces and control (3).
Fig.8. Antibacterial efficacy indicated by the inhibtion zones (mm diam) exhib-
ited by biosynthesized silver nanoparticles against E. coli (A), S. aureus (B), P.
aeruginosa (C), S. typhi (D) and P. mirabilis (E) using AgNPs alone (1), commer-
cial antibiotic Gentamycin (2) and a combination of AgNPs with Gentamycin (3)
Fig.7. Inhibition zones exhibited by two concentrations of silver nanoparticles
from the fungus Curvularia tuberculata against five strians of pathogenic bacteria
Table 2. The minimal inhibitory concentrations (MIC) and mini-
mal bactericidal concentrations (MBC) of biosynthesized AgNPs
against two strains of bacteria
Bacteria
MIC
(μg/ml)
MBC
(μg/ml)
E. coli E. coli E. coli
E. coli 0.00976 0.0195
Antibacterial efficacy of synthesized AgNPs combined with
Gentamycin
The antibacterial efficacy of AgNPs combined with commercial
antibiotic Gentamycin was significantly (P ≤ 0.05) increased
against the growth of the tested strains of bacteria compared with
activity of either of them alone (Fig. 8). Over all the tested bacteria,
the growth inhibition zones ranged between 26-34 mm diameter
(Table 3). Among the examined bacteria, the growth of S. typhi
and P. mirabilis was remarkably inhibited by silver nanoparticles
combined with Gentamycin as indicated by the increase in fold
area values (0.0.284, 0.299 and 0.322, respectively) (Table 3).
Bacteria ANPs
Gentmycin
(Ge)
AgNPs
+
Ge
increase
in fold
area
E. coli 16* 22.5 25.5 0.284**
S.aureus 15.5 28 29.5 0.110
P. aeruginosa 17 25 28.5 0.299**
S. typhi 17 32.5 35.5 0.159
P. mirabilis 11.5 30 34.5 0.322**
Numbers represent mean of three replicates*
**Significant difference at P ≤0.05
Table 3. Inhibition zones exhibited by the silver nanoparticles
(AgNPs) combined with commercial antibiotic Gentamycin (Ge)
against five bacteria strains and the calculated increase in fold area
Inhibition Zone (mm diameter)

5. Cite this article:Muhsin T M, Hachim A K(2014).Characterization and antibacterial efficacy of silver nanoparticles biosynthesized by the soil fungus Curvularia tuberculata, NanoSciTech Open Lib, 1(1): 5-11.
Science Fair Open Library | Inspiring the World of Science 2015 | Volume 1 | Issue 1 |NSTOL1114001006
Discussion
Fungi are good natural sources for biosynthesis of nanoparticles
due to their capability of producing extracellular metabolites
containing metal nanoparticles such as silver nanoparticles [14].
Moreover, fungi are common in nature, eco-friendly and can be
easily cultivated on media. Although the mechanistic involved
the biosynthesis of silver nanoparticles by fungi are still question-
able, however, there are some proposals which are addressed by
researchers. Duran et al. [4] has proposed that silver nanoparticles
biosynthesis depends on the enzyme reductase which is responsi-
ble for the reduction ofAg+
ions and subsequently formation ofAg-
NPs. Furthermore, a reduction of Ag+
may be due to a conjugation
between the electrons shuttle with reductase enzyme involvement
[19]. On the other hand, it is believed that silver nanoparticles are
produced on fungal hyphal surface by trapping of Ag ions via the
electrostatic interaction between Ag+
ions and the negative charges
of carboxylate groups within the protein of the fungal hyphal cell
walls [17, 22]. Nevertheless, the last decade has witnessed an in-
creased research interests focusing on the mycosynthesis of silver
nanoparticles as an agent widely used in biomedical applications
[15, 24, 32]. However, silver nanoparticles are of a particular im-
portance as antimicrobial agent [6, 35]. The present study showed
that the selected fungus Curvularia tuberculata exhibited high po-
tentiality for synthesis of silver nanoparticles in culture medium as
indicated by the color change from yellow into dark brown after
72 hrs of incubation after being treated with 1 mM AgNO3
solu-
tion. These findings are in conformity with other previous studies
using different fungal species, for example, Fusarium oxysporum,
F. acuminatum and Phoma glomerata [1, 2, 12, 29]. It has been
explained that the color change after addition of AgNO3
to the
fungal free-cell filtrate is due to the excitation of surface plasmon
resonance vibration of silver that confirmed the reduction of silver
ions as stated by Chitra and Annadurai [3]. UV-Vis spectropho-
tometry is often used as a technique for analyzingAgNPs synthesis
[11]. The present findings revealed that UV-Vis spectrophotom-
etry analysis showed a sharp peak with high absorbance at 420
nm which verified the AgNPs synthesis by the examined fungus
and a completed biosynthesis of AgNPs was after 72 h of free-cell
filtrate incubation. This is in agreement with some other studies [3,
12]. However, in comparison with some other previous studies [2,
3, 12, 29], apparently that there are some differences among the
time of biosynthesis of silver nanoparticles and their UV-spectra
recorded by examining different species of fungi. Such variations
in characterization of silver nanoparticles biosynthesis might be
related to the source of fungal species or strains as well as the fun-
gal culture conditions applied as previously stated [21]. The pres-
ent study revealed that the shape of AgNPs were mainly spherical
and dispersed with size of 10-50 nm as confirmed by SEM images.
Another study [20] has reported that the size of silver particles
ranges between 7-89 nm. Our recent study [21] reported that the
size of silver nanoparticles produced by Nigrospora sphaerica was
ranged between 20-70 nm. It has been stated that the absorption
spectrum of spherical shape of silver nanoparticles present a maxi-
mum between 420-450 nm [23]. Analysis of FTIR indicated the
release of proteins into fungal filtrate which causes a reduction
of silver ions present in the free-cell filtrate. The reduction of the
Ag+
ions can be attributed to the enzyme reductase that released by
the fungus as reported by Gole et al. [10]. It has been speculated
that FTIR analysis has indicated that peptides are binding with the
silver nanoparticles forming a capping agent of nanoparticles and
stabilizing them in the fungal culture medium [33].
In this study two concentrations 50 µl/ml and 100µl/ml
of silver nanoparticles synthesized by the fungus C. tuberculata
were examined against the selected pathogenic bacterial strains
and rendered a significant bacterial growth inhibition as indicated
by the appearance of bacterial inhibition clear zones. However,
variations among the antibacterial efficacy exhibited by the silver
nanoparticles were observed. Higher inhibition zones diameters
was recorded for P. aeruginosa, S. aureus and S. typhi. Although
the mechanism of AgNPs on the bacterial growth is not yet well
verified, however, it can be related to the impact of Ag ions by
causing cell membrane damage, DNAdenaturation, enzymes dam-
age or due to some other effects [7, 16, 19, 24].
The minimum inhibitory concentration (MIC) of the silver
nanoparticles showed that the MIC values were 0.312 µg/ ml and
0.0097 µg/ ml against E. coli and S. aureus, respectively. The MIC
values were very low indicating that a high potential activity of
biosynthesized silver nanoparticles against Gram positive and
Gram negative bacteria. Similar findings were reported by other re-
searchers using AgNPs synthesized from other fungi against Gram
positive and Gram negative bacteria [19, 20]. More recent study by
Muhsin and Hachim [21] has explored that the soil fungus Nigros-
pora sphaerica exhibits high capability for biosynthesis of silver
nanoparticles and revealed a high antibacterial activity against five
strains of human pathogenic bacteria. The present study has also
examined the antibacterial efficacy of the mycosynthesized silver
nanoparticles combined with the commercial antibiotic Gentamy-
cin and revealed that the efficiency of silver nanoparticles with
Gentamycin was found to be remarkably increased reaching be-
tween 35.5 mm and 34.5 mm diameter inhibition zone against S.
typhi and P. mirabilis, respectively. The antibacterial activity of
a combination of AgNPs with Gentamycin was expressed as in-
crease in fold area according to Birla et al. [2]. Our results sup-
port some other studies examined the synergistic effects of AgNPs,
synthesized from various fungal species, in a combination with
different commercial antibiotics tested against Gram positive and
Gram negative bacteria [6, 9, 31]. It can be concluded that the se-
lected novel fungus C. tuberculata has a potentiality for synthesis
of silver nanoparticles which exhibiting a high growth inhibition
and a wide spectra efficacy against Gram positive and negative
pathogenic bacteria. In general fungi represent a natural resource
and can be implemented in pharmaceutical industry and medical
therapy, hence, further researches to explore more potent fungal
species to synthesize silver nanoparticles are needed. Optimiza-
tion of biosynthesis of silver nanoparticles and their antimicrobial
activities are also recommended. Furthermore, mechanistic studies
to understand the biosynthesis of silver nanoparticles from fungi
are important.
Page 9

6. Cite this article:Muhsin T M, Hachim A K(2014).Characterization and antibacterial efficacy of silver nanoparticles biosynthesized by the soil fungus Curvularia tuberculata, NanoSciTech Open Lib, 1(1): 5-11.
Science Fair Open Library | Inspiring the World of Science 2015 | Volume 1 | Issue 1 |NSTOL1114001006
1. Ahmad A, Mukherjee P, Senapati S, Mandal D, Khan MI,
Kumar R, Sastry M (2003) Extracellular biosynthesis of silver
nanoparticles using the fungus Fusarium oxysporum. Colloid
Surf 28: 313-318
2. Birla S, Tiwari VV, Gade AK, Ingle AP, Yadav AP, Rai MK
(2009) Fabrication of silver nanoparticles by Phoma glomerata
and its combined effect against Escherichia coli, Pseudomonas
aeruginosa and Staphylococcus aureus. Lett Appl Microbiol
48: 173-179
3. Chitra K, Annadurai G (2013) Bioengineered silver nanobowls
using Trichoderma viride and its antibacterial activity against
Gram-positive and Gram-negative bacteria. J Nanostruct
Chem 39: 3-9
4. Duran N, Marcato PD,Alves OL, Desouza G, Esposito E (2005)
Mechanistic aspects of biosynthesis of silver nanoparticles by
several Fusarium oxysporum Strains. J Nanobiotechnol 3:1-8
5. Ellis MB (1971) Dematiaceous hyphomycetes. Common-
wealth Mycol Inst Kew Surrey, England.
6. Fayaz AM, Balaji K, Girilal M, Yadav R, Kalaichelvan PT,
Venketesan R (2010) Biogenic synthesis of silver nanoparti-
cles and their synergistic effect with antibiotics: a study against
Gram positive and Gram-negative bacteria. Nanomed 6: 103-
109
7. Feng QL, Wu J, Chen GQ, Cui FZ, Kim TN, Kim JO (2000) A
mechanistic study of the antibacterial effect of silver ions on
Escherichia coli and Staphylococcus aureus. J Biomed Mater
Res 52: 662-668
8. Gade AK, Ingle A, Whiteley C, Rai M (2010) Mycogenic met-
al nanoparticles: Progress and applications. Biotechnol Lett
32: 593-600
9. Gajbhiye M, Kesharwani J, Ingle A, Gade A, Rai M (2009)
Fungus-mediated synthesis of silver nanoparticles and their
activity against pathogenic fungi in combination with flucon-
azole. Nanomed Nanotech Bio Med 5: 382-386
10. Gole A, Dash C, Ramakrishnan V, Sainker SR, Mandale AB,
Rao M. Sastry M (2001) Pepsin-gold colloid conjugates: prep-
aration, characterization and enzymatic activity. Langmuir 5:
1674-1679
11. Henglein A (1993) Physiochemical properties of small metal
particles in solution: microelectrode” reaction, chemisorption,
composite metal particles and the atom-to-metal transition. J
Physic Chem 7: 5457-5471
12. Ingle A, Gade A, Pierrat S, Sonnichsen C, Rai M (2008) My-
cosynthesis of silver nanoparticles using the fungus Fusarium
acuminatum and its activity against some human pathogenic
bacteria. Curr Nanoscie 4: 141-144
13. Karbasian M, Atyabi SM, Siyadat SD, Momen SB, Norouzian
D (2008) Optimizing nano-silver formation by Fusarium oxy-
sporum PTCC5115 employing response surface methodology.
Am J Agric Biol 3:433-437
14. Kashyap PL, Kumar S, Srivastava AK, Sharma AK (2013)
Myconanotechnology in agriculture: a perspective. World J
Microbiol Biotechnol 29: 191-207
15. Kearns GJ, Foster EW, Hutchison JE (2006) Substrates for
direct imaging of chemically functionalized SiO2 surfaces by
transmission electron microscopy. Anal Chem 78: 298–303
16. Kim JS, Kuk E, Yu KN, Kim JH, Park SJ, Lee HJ, Kim SH,
Park YK, Park YH, Hwang CY (2007) Antimicrobial effects
of silver nanoparticles. Nanomed. 3: 95-101
17. Maliszewska I, Szewezk K, Waszak K (2009) Biological syn-
thesis of silver nanoparticles. J Physic 146: 1-6
18. Manimozhi R and Anitha R (2014) Mycosynthesis of silver
nanoparticles using aqueous extract of Aspergillus flavus my-
celium and its characterization. Internat J Pharma Drug Anal 2:
734-739
19. Marambio-Jones C, Hoek EMV (2010) A review of the anti-
bacterial effects of silver nanomaterilas and potential implica-
tions for human health and the environment. J Nanopart Res
12: 1531-1551
20. Matrinez-Castanon GA, Nino-Martinez N, Matinez-Gutierrez
F, Martinez-Mendoza JR, Ruiz F (2008) Synthesis and anti-
bacterial activity of silver nanoparticles with different sizes. J
Nanopart Res 10: 1343--1348
21. Muhsin TM, Hachim AK (2014) Mycosynthesis and character-
ization of silver and their activity against some human patho-
genic bacteria. World J Microbiol Biotechnol 30: 2081-2090
22. Mukherjee P, Roy M, Mandal BP, Dey GK, Mukherjee PK,
Ghatak J, TyagiAK, Kale SP (2008) Green synthesis of highly
stabilized nanocrystalline silver particles by a non-pathogenic
and agricultural important fungus T. asperellum Nanotechnol.
19: 75-103
23. Pal S, Tak YK, Song JM (2007) Does the antibacterial activity
of silver nanoparticles depend on the shape of nanoparticles?
A study of the Gram negative bacterium Escherichia coli. Appl
Environ Microbiol 73: 1712-1720
24. Prabhu S and Poulose EK (2012) Silver nanoparticles: Mecha-
nism of antibacterial action, synthesis, medical applications
and toxicity. Internat J Nano Lett 2: 32-42
25. Perez C, Paul M, Bazerque P (1990) Antibiotic assay by agar
well diffusion method. Acta Biol Med.Exp 15: 113-115
26. Qi L, Xu Z, Jiang X, Hu C, Zou X (2004) Preparation and
antibacterial activity of chitosan nanoparticles. Carbohyd Res
16: 2693- 2700
27. Raheman F, Deshmukh S, Ingle A, Gad A, Raj M (2011) Silver
nanoparticles: Novel antimicrobial agent synthesized from an
endophytic fungus Pestalotia sp. Isolated from leaves of Syzy-
gium cumini L. Nano Biomed Eng 3:174-178
28. Rai M, Yadav A, Bridge P, Gade A, Rai MK, Bridge PD (2009)
In: Rai, M, Bridge PD (eds) Applied mycology myconano-
technology: a new and emerging science, CAB International,
New York, pp. 258–267
Page 10
References
© 2015 Muhsin T.M, Hachim A.K, et al. Published
by the Science Fair Open Library under the terms of the Creative
Commons Attribution 4.0 International License. The images or
other third party material in this article are included in the ar-
ticle’s Creative Commons license, unless indicated otherwise in
the credit line; if the material is not included under the Creative
Commons license, users will need to obtain permission from
the license holder to reproduce the material.To view a copy of
this license, visit http://creativecommons.org/licenses/by/4.0/
Copyright:
The authors would like to thank the au-
thorities of Biology Department, College of Education for Pure
Sciences, Basra University (Iraq) for support of this research
work as a part of MSc. research program scholarship awarded
to the second author.
Funding: -
Acknowledgements:

7. Cite this article:Muhsin T M, Hachim A K(2014).Characterization and antibacterial efficacy of silver nanoparticles biosynthesized by the soil fungus Curvularia tuberculata, NanoSciTech Open Lib, 1(1): 5-11.
Science Fair Open Library | Inspiring the World of Science 2015 | Volume 1 | Issue 1 |NSTOL1114001006
29. Riddin TL, Gericke M, Whiteley CG (2006) Analysis of the
inter and extracellular formation of platinum nanoparticles by
Fusarium oxysporum f. sp. lycopersici using response surface
methodology. Nanotechnol. 17: 3482-3489
30. Sadawiski Z, Maliszewska IH, Grochwalska B, Polowezyk I,
Kozlechi T (2008) Synthesis of silver nanoparticles using mi-
croorganisms. J Mater Sci 26: 410-424
31. Shahverdi AR, Fakhimi A, Shahverdi HR, Minaian S (2007)
Synthesis and effect of silver nanoparticles on the antibacterial
activity of different antibiotics against Staphylococcus aureus
and Escherichia coli. Nanomed. 3:168-171
32. Sharma VK, Yingard RA, Lin Y (2009) Silver nanoparticles:
green synthesis and their antimicrobial activities. Advanc Col-
loi Interf Sci 145: 83-96
33. Vigneshwaran N, Ashtaputre NM, Varadarajan PV, Nachane
RP, Paralikar KM, Balasubramanya RH (2007) Biological syn-
thesis of silver nanoparticles using the fungus Aspergillus fla-
vus. Mater Lett 261: 1413-1418
34. Watanabe T (2002) Pictorial atlas of soil and seeds fungal mor-
phologies of cultured fungi and key to species. CRC press,
USA.
35. Yokoyama K, Welchons K (2007) The conjugation of amyloid
beta protein on the gold colloidal nanoparticles surfaces. Nano-
technol. 18: 105-110
Page 11