Biosynthesis of Silver Nanoparticles by Aspergillus terreus: Characterization, Optimization, and Biological Activities (original) (raw)
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OPTIMAL FACTORS FOR BIOSYNTHESIS OF SILVER NANOPARTICLES BY ASPERGILLUS SP
In the present study, an eco-friendly process for the synthesis of nanomaterials using a fungus, Aspergillus sp has been attempted. The biosynthesized AgNPs optimization was studied. Silver nanoparticles (Ag-NPs) were extracellular biosynthesized using Aspergillus sp isolated from Helwan cement factory, Helwan governorate, Egyp t. The biosynthesis of AgNPs is usually accompanied with changing in the color from light yellow to brow n graduall y. The optimum conditions for pure fungal isolate to biosynthesis of AgNPs was grown in a Czapex Dox broth med i u m at 32 ± 2°C for 5 days, pH 6 in a shaker incubator at 150 rpm to produce reductase enzymes which convert Ag+ to Ag 0 in 100 ml distilled water. Biomass filtrate treated with 1.5 mM of AgNO3 silver nitrate at pH 10 and kept for 2 4 hr at 35°C. Control was prepared without addition of silver nitrate solution. The nanoparticles synthesized sh o w ed an absorption peak at 400 nm in UV-Vis spectrum corresponding to the Plasmon resonance of silver nanoparticles.
Biological Synthesis of Silver Nanoparticles from Aspergillus fumigatus
The synthesis of nanoparticles from the microbes isa boon for advance research in nanotechnology. In this study, silver nanoparticles were synthesized using the fungus Aspergillus fumigatuswith an aqueous solution of AgNO3. Synthesized silver nanoparticles (Ag-NPs) were characterized through UV-visible spectrophotometer and Fourier Transform Infrared Spectroscopy (FTIR). Maximum absorbance was observed at 420 nm in visible region. The nature of coordination between bioactive compounds secreted by fungi and silver ions were analyzed through FTIR spectroscopy. The reduction of silver ions was due to amino groups of proteins and other functional groups in the cellfree filtrate of fungi. The reduction of silver ions leads to the formation of stable protein capped silver nanoparticles. The Ag-NPs andAg-NPs + Chloramphenicol (Ab) possess potential antimicrobial activity against to Escherichia coli, Klebsiella pneumonia, Bacillus cereus, Staphylococcus aureus and Streptococcus sp.
Nanoscience and Nanotechnology Letters, 2014
ABSTRACT Optimal conditions for the biosynthesis of silver nanoparticles (AgNPs) by fungi Aspergillus foetidus were investigated. Condition of 0.2% salinity, 4 mM of AgNO3, pH 9, 10% diluted concentration of cell filtrate and incubation time of 72 h at 30 �C were found to be optimum for the biosynthesis of silver nanoparticles. The activity of nitrate reductase attained optimum level at 0.2% salinity, pH 9 and 30 �C. Activities of nitrate reductase in fugal cell filtrate were 0.5116 and 0.1711 �mol/ml/min, respectively, before and after the synthesis of AgNPs. The protein contents were 407.4 and 207.3 �g/ml respectively before and after the synthesis of AgNPs, and both the nitrate reductase activity and the protein content decreased after the biosynthesis of AgNPs, indicating a possible role for this enzyme in the biosynthesis of AgNPs. The rate of conversion of Ag+ to Ag0 and the concentration of the synthesized Ag0 were found to be 93.39% and 158.65 �g/ml, respectively. The minimum inhibitory concentration (MIC) of synthesized AgNPs was determined against selected plant pathogenic fungi of Aspergillus spp. and F. oxysporum, and MIC value of AgNPs in A. flavus was lowest 1.6 �g/ml.
Exploitation of Aspergillus niger for fabrication of silver nanoparticles
Extracellular biosynthesis of silver nanoparticles by Aspergillus niger isolated from soil is being reported in the present paper. The production of silver nanoparticles was evidenced by UV-vis spectrum, showing the absorbance at 420 nm (Perkin Elmer Lambda-25). The nanoparticles characterized by Transmission Electron Microscopy exhibited spherical silver nanoparticles with diameter of around 20 nm. Elemental Spectroscopy imaging showed the presence of fungal protein around the silver nanoparticles thereby increasing their stability in the suspension. The silver nanoparticles (10 g/ml) showed remarkable antibacterial activity against gram-positive (Staphylococcus. aureus) and gram-negative (Escherichia coli) bacteria. The reduction of the silver ions might have occurred by a nitrate-dependent reductase enzyme and a shuttle quinone extracellular process. Reduction of silver ions was an extracellular and rapid process; this knowledge may lead to the development of an easy process for biosynthesis of the silver nanoparticles. Potential of fungal-mediated biosynthesis of silver nanoparticles is important for development of effective antibacterial agents showing resistance to drugs available in the market.
IJMTST, 2020
Extracellular biosynthesis of silver nanoparticles by fungus Aspergillus niger which was isolated from waste water is being reported in the present paper. The production of silver nanoparticles was evidenced by UV-Vis spectrum, showing the absorbance between 260 to 400 nm. The nanoparticles characterized by Scanning Electron Microscopy exhibited silver nanoparticles with diameter of 25nm to 75nm. Energy Dispersive X-ray analysis reveals strong signals in the silver region and confirms the formation of the silver nanoparticles. The Fourier Transform Infrared Spectroscopy study confirmed that the A. niger mycomass has the ability to perform both reduction and capping functions on the silver nanoparticles. Compound Microscopy confirms the self-assembling property of silver nanoparticles. The silver nanoparticles showed remarkable antibacterial activity against Lactobacillus plantarum, Lactobacillus delbrueckii and Bacillus subtilis bacterial strains. Reduction of silver ions is an extracellular and rapid process; this information may lead to the development of easy protocols for biosynthesis of the silver nanoparticles. Antibacterial activity of silver nanoparticles is important for the development of effective antibacterial agent against those bacteria who are showing resistance against antibiotic drugs which are available in market.
Optimal conditions for the biosynthesis of silver nanoparticles (AgNPs) by fungi Aspergillus foetidus were investigated. Condition of 0.2% salinity, 4 mM of AgNO3, pH 9, 10% diluted concentration of cell filtrate and incubation time of 72 h at 30 C were found to be optimum for the biosynthesis of silver nanoparticles. The activity of nitrate reductase attained optimum level at 0.2% salinity, pH 9 and 30 C. Activities of nitrate reductase in fugal cell filtrate were 0.5116 and 0.1711 mol/ml/min, respectively, before and after the synthesis of AgNPs. The protein contents were 407.4 and 207.3 g/ml respectively before and after the synthesis of AgNPs, and both the nitrate reductase activity and the protein content decreased after the biosynthesis of AgNPs, indicating a possible role for this enzyme in the biosynthesis of AgNPs. The rate of conversion of Ag+ to Ag0 and the concentration of the synthesized Ag0 were found to be 93.39% and 158.65 g/ml, respectively. The minimum inhibitory concentration (MIC) of synthesized AgNPs was determined against selected plant pathogenic fungi of Aspergillus spp. and F. oxysporum, and MIC value of AgNPs in A. flavus was lowest 1.6 g/ml.
Journal of Nanomaterials
The biogenesis of silver nanoparticles by fungi is an ecologically clean and nontoxic method compared to other physical and chemical methods. Thus, we aimed to discuss the mycosynthesis of extracellular size-controlled AgNPs. After comprehensive screening, Aspergillus fumigatus BTCB10 (KY486782) was selected for the synthesis of AgNPs of controlled size. Characterization was performed by UV-Vis spectrophotometer, Zetasizer, X-Ray Diffraction (XRD), FTIR (Fourier-transform infrared), Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM) along with functional assays—antibacterial and MTT assays. Data suggested that under optimized conditions, i.e., temperature 25°C, AgNO3 concentration 1 mM, biomass 7 g, fungal culture age 7 days, pH 6, ratio of cell-free filtrate (CFF)/silver nitrate (3 : 2), NaCl 20%, and under dark light, the smallest size AgNPs of 0.681 nm with 100% monodispersity was obtained as evident by a zeta potential of -23.4 mV, UV-Vis band at 400 nm, and t...
BIOLOGICAL SYNTHESIS OF SILVER NANOPARTICLES USING FUNGUS ASPERGILLUS NIGER AND ITS CHARACTERIZATION
Synthesis of silver nanoparticles using fungi is emerging as an important branch of nanotechnology due to its ecofriendly, safe, and cost-effective nature. The present work investigates the synthesis of silver nanoparticles by biological method using fungus Aspergillus niger. The test fungus was isolated from decayed banana fruit in PDA. Based on identification using morphological characteristics, Aspergillus niger was identified. The production of silver nanoparticles by the fungus Aspergillus niger was investigated. It was found that exposure of Aspergillus niger to silver ion leads to the formation of silver nanoparticles. Synthesized nanoparticles were characterized by UV-Vis spectroscopy and the peak of the spectra was found to be at 420nm. The morphological study of Silver nanoparticles using TEM suggests that the nanoparticles are spherical in shape with a diameter around 50-100nm. The TEM characterization of the fungus reacted on the silver ion indicated that the protein might be responsible for the stabilization of the silver nanoparticles. The rapid synthesis of silver nanoparticles would be suitable for developing a "microbial nanotechnology" biosynthesis process for mass scale production.
Exploitation of Aspergillus niger for Synthesis of Silver Nanoparticles
Journal of Biobased Materials and Bioenergy, 2008
Extracellular biosynthesis of silver nanoparticles by Aspergillus niger isolated from soil is being reported in the present paper. The production of silver nanoparticles was evidenced by UV-vis spectrum, showing the absorbance at 420 nm (Perkin Elmer Lambda-25). The nanoparticles characterized by Transmission Electron Microscopy exhibited spherical silver nanoparticles with diameter of around 20 nm. Elemental Spectroscopy imaging showed the presence of fungal protein around the silver nanoparticles thereby increasing their stability in the suspension. The silver nanoparticles (10 g/ml) showed remarkable antibacterial activity against gram-positive (Staphylococcus. aureus) and gram-negative (Escherichia coli) bacteria. The reduction of the silver ions might have occurred by a nitrate-dependent reductase enzyme and a shuttle quinone extracellular process. Reduction of silver ions was an extracellular and rapid process; this knowledge may lead to the development of an easy process for biosynthesis of the silver nanoparticles. Potential of fungal-mediated biosynthesis of silver nanoparticles is important for development of effective antibacterial agents showing resistance to drugs available in the market.
Iranian Journal of Biotechnology, 2010
In this study, silver nanoparticles were synthesized using the fungus, Aspergillus fumigatus. The effects of three independent variables including glucose content of culture media, initial pH and initial spore concentration on biosynthesis of silver nanoparticles were investigated. These variables affect cell morphology, cell mass, size and morphology of silver nanoparticles and degree of silver ion reduction. The formation of silver nanoparticles was confirmed spectrophotomterically. Size and morphology of silver nanoparticles were investigated using transmission electron microscopy (TEM). The effects of culture conditions on cell mass concentration as well as the amount and size of synthesized silver nanoparticles were studied. As a result, the optimum culture condition for biosynthesis of silver nanoparticles consisted of a glucose concentration of 16 g/l, pH of 4.5 and spore concentration of 1.5×10 7 spore/l. TEM micrographs showed that the size of nanoparticles in the sample synthesized under optimized condition was in the range of 7-19 nm.