Biogenic Synthesis of Silver and Gold Nano Particles using Fungal Species (original) (raw)
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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.
2014
In this study, we investigated the fungus Aspergillus terreus used for the biosynthesis of silver and gold nanoparticles. The cell free filtrate of Aspergillus terreus reacted with AgNo3 and HAuCl4 ions separately, resulting formation of silver and gold nanoparticles. The silver and gold nanoparticles were characterized by Visual analysis, UV-Vis absorption spectroscopy and Transmission electron microscopy (TEM). The silver and gold nanoparticles exhibited maximum absorbance at 430 and 540 nm in UVVis spectroscopy.TEM micrograph showed polydisperse spherical and ellipsoid nanoparticles in the size range from 1-50 nm. Aspergillus terreus synthesizedsilver nanoparticles found strong antibacterial activity against Staphylococcus aureus and Shigella sps. Howevergold nanoparticles do not showed any antibacterial activity. Biological approach using the fungi is a novel way towards the safe, cost effective and ecofriendly method for the synthesis of gold nanoparticles is gaining importance...
Green synthesis of silver nanoparticles: The reasons for and against Aspergillus parasiticus
Objective(s): The enzymatic activity of fungi has recently inspired the scientists with re-explore the fungi as potential biofactories rather than the causing agents of humans and plants infections. In very recent years, fungi are considered as worthy, applicable and available candidates for synthesis of smaller gold, silver and other nano-sized particles. Materials and Methods: A standard strain of Aspergillus parasiticus was grown on a liquid medium containing mineral salt. The cell-free filtrate of the culture was then obtained and subjected to synthesize SNPs while expose with 1mM of AgNO3. Further characterization of synthesized SNPs was performed afterward. In addition, antifungal activity of synthesized SNPs was evaluated against a standard strain of Candida albicans. The reduction of Ag+ ions to metal nanoparticles was investigated virtually by tracing the color of the solution which turned into reddish-brown after 72h. Results: The UV-vis spectra demonstrated a broad peak centering at 400nm which corresponds to the particle size much less than 70nm. The results of TEM demonstrated that the particles were formed fairly uniform, spherical, and small in size with almost 90% in 5-30nm range. The zeta potential of silver nanoparticles was negative and equal to -15.0 which meets the quality and suggested that there was not much aggression. Silver nanoparticles synthesized by A. parasiticus showed antifungal activity against yeast strain tested and exhibited MIC value of 4 μg/mL. Conclusion: The filamentous fungus, A. parasiticus has successfully demonstrated potential for extra cellular synthesis of fairly monodispersed, tiny silver nanoparticles.
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.
Fungi-assisted silver nanoparticle synthesis and their applications
Bioprocess and biosystems engineering, 2017
Nanotechnology is a rapidly developing field because of its wide range of applications in science, nanoscience and biotechnology. Nanobiotechnology deals with nanomaterials synthesised or modified using biotechnology. Fungi are used to synthesise metal nanoparticles and they have vast applications in wound healing, pathogen detection and control, food preservation, textiles, fabrics, etc. The present review describes the different types of fungi used for the biosyntheses of silver nanoparticles (AgNPs), along with their characterisation and possible biological applications. AgNPs synthesised by other physical and chemical methods are expensive and have toxic substances adsorbed onto them. Therefore, green, simple and effective approaches have been chosen for the biosynthesis of AgNPs, which are very important because of their lower toxicity and environmentally friendly behaviour. AgNPs synthesised using fungi have high monodispersity, specific composition and a narrow size range. In...
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.
Journal of Fungi
Fungi’s ability to convert organic materials into bioactive products offers environmentally friendly solutions for diverse industries. In the nanotechnology field, fungi metabolites have been explored for green nanoparticle synthesis. Silver nanoparticle (AgNP) research has grown rapidly over recent years mainly due to the enhanced optical, antimicrobial and anticancer properties of AgNPs, which make them extremely useful in the biomedicine and biotechnology field. However, the biological synthesis mechanism is still not fully established. Therefore, this study aimed to evaluate the combined effect of time, temperature and pH variation in AgNP synthesis using three different fungi phyla (Ascomycota, Basidiomycota and Zygomycota) represented by six different fungi species: Cladophialophora bantiana (C. bantiana), Penicillium antarcticum (P. antarcticum), Trametes versicolor (T. versicolor), Trichoderma martiale (T. martiale), Umbelopsis isabellina (U. isabellina) and Bjerkandera adus...