جستجوی مقالات مرتبط با کلیدواژه « بیوسنتز » در نشریات گروه « زیست شناسی »

Urinary tract infections have significant complications and high costs and can lead to death. Appropriate treatment has been challenged due to high drug resistance. The aim of the present study was the biosynthesis of zinc oxide nanoparticles/banana peel on multi-drug resistant uropathogenic bacteria in children under two years of age.

In this study, bionanoparticles of zinc oxide/banana peel were synthesized and the structural, optical, morphological, and particle size characteristics were investigated using X-ray diffraction, ultraviolet absorption spectrum, and scanning electron microscopy. Biochemical tests and Colony-PCR technique were used to identify bacteria. The antibacterial properties of the synthesized nanoparticles were evaluated by the Agar dilution method on isolated bacteria.

According to the XRD, SEM, and UV-Vis results, the synthesized zinc oxide had a hexagonal structure with a size of 100 nm and absorption at a wavelength of 258 nm. Bacterial strains of Escherichia coli, Proteus mirabilis and Klebsiella pneumoniae multidrug-resistant Uropathogenic bacteria were identified using morphological, biochemical, and molecular characteristics. The results of antibacterial tests showed that bionanoparticles of zinc oxide/banana peel at a concentration of 0.6 g/L were effective against all bacteria.

The findings of this research showed that zinc oxide/banana peel bio-nanoparticles had an effective antibacterial effect against multi-drug resistant UTI bacteria in children under two years of age.

Aloe vera L. is one of the oldest and most traditional medicinal plants in history, which is more than a thousand years old. Today, its biological activity is not limited to therapeutic purposes. The expansion of the Aloe vera L. industry became evident during the 90s when the development of this product began due to the global demand from consumers for a healthier lifestyle. Considering this plant's relationship with agriculture, industry, and the economy, the present work examined   chemical, biological, and nutritional properties of Aloe vera and its processing methods, innovations, and biosynthesis of nanoparticles, and industrial applications. Applications of this plant are detailed in pharmaceutical, cosmetic, and food industries, and the global vision of the million-dollar market around this product is discussed. Also, the biosynthesis method of nanoparticles using Aloe vera L. as a reducing agent is presented. Aloe vera L. has been used to produce nanomaterial through biosynthesis. This plant has many unique properties and is known for its antioxidant, anti-inflammatory, anti-diabetic, sunburn relief, immune system strengthening, anti-aging, and anti-cancer properties. The study concludes that biosynthesized nanoparticles with Aloe vera L. are environmentally friendly, simple, economical, and safe.

Silver nanoparticles have been widely used due to their anti-bacterial activities and anticancer properties. The aim of this study was to investigate the antimicrobial effects and cell toxicity of silver nanoparticles synthesized using extracts of chamomile on three neoplastic cell lines (A549, MCF-7 and HeLa).

Silver nanoparticles were biologically synthesized using extracts of chamomile. After physical and chemical evaluation of the synthesized nanoparticles, their antimicrobial properties were estimated on Escherichia coli and Staphylococcus aureus. Finally, the inhibitory effect of synthesized nanoparticles evaluated by using MTT technique on 3 neoplastic cell lines.

  The average size of nanoparticles synthesized by the extract of chamomile were 19 nm. The synthesized nanoparticles could have a significant inhibitory and lethal effect on the two named bacteria. silver nanoparticles were able to show a 50% inhibitory effect on different cell lines at a concentration of 50 μg/ml.

Based on the results, it can be stated that medicinal plants can be used in the successful biosynthesis of silver nanoparticles. After human studies and tests, chamomile-based silver nanoparticles can be used as effective therapeutic agent in the treatment of some cancers due to their coating of effective secondary metabolites and the release of silver ions (Ag+).

This study aimed to isolate and identify the silver-resistant bacteria and investigation on their potential in the biological synthesis of silver sulfide nanoparticles (Ag2SNPs).

Preliminary characterization of the Ag2SNPs was carried out using visual observations and UV–Visible spectroscopy. Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) was used to determine size, morphology, and elemental analysis of the nanoparticles. Fourier-transform infrared spectroscopy (FTIR) analysis was performed to determine the functional groups that are involved in the bioreduction of silver sulfate into Ag2SNPs.

Based on the results, Bacillus safensis strain GMS10 with highest tolerance to silver sulfate (50 mM) was able to synthesize spherical shape of Ag2SNPs with an average size diameter of 22.2 nm under optimized conditions (1 mM silver sulfate, 15 g/L biomass) after 36 hours incubation. This study is the first report on the synthesis of Ag2SNPs using B. safensis.

Nanoscale science and technology the production of matter in nanometer dimensions and exploitation of its properties in modern systems. Today, one of the most efficient methods of nanoparticle synthesis is the method of green synthesis or biosynthesis of nanoparticles by plants. The purpose of this study was to synthesize and develop a green method for the preparation of iron nanoparticles. In this study, iron nanoparticles were synthesized in a process by the extract of Russian knapweed (Acroptilon repens L.) which containing phenolic compounds. The extract of the plant was obtained by maceration method. The co-precipitation method was used to prepare iron nanoparticles with the extract of Acroptilon repens L. The samples were analyzed by Thermo Gravimetric Analysis (TGA), Fourier transform infrared (FT-IR), Vibrating Sample Manetometer (VSM), Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). In Spectrophotometric analysis, the presence of a peak in the range of 490 to 600 nm indicates the biological synthesis of these nanoparticles with extract of Acroptilon repens. The size and morphology of biologically synthesized nanoparticles were determined by scanning electron microscopy, and it was found that the shape of the polygonal and round particles and their average size are about 39 to 50 nanometers. The results of X-ray diffraction analysis also showed the nanocrystals synthesized extract of Acroptilon repens. According to the results, it can be said that the polyphenolic compounds in the Acroptilon repens. extract were acted as iron-metal reducing agents, and also as a complexing agent synthesize iron nanoparticles and make them sustainable

Today, nanosilver is one of the most commercialized nanomaterials. The demand for synthesis of Nanosilver through biocompatible routs due to wide biomedical application has increased. Use of plants and plant products as sustainable and renewable resources in the synthesis of nanoparticles is more advantageous over other biological routes. In this study, biosynthesis of silver nanoparticles (AgNPs) using aqueous extract of Withania somnifera as reducing agent is reported. Effect of parameters such as AgNO3 concentration, aqueous extract, pH and formation time were investigated and optimized by UV-visible spectroscopy in the synthesis of nanoparticles. At room temperature, the solution color started to change from pale yellow to dark brown due to the reduction of silver ion. The transmission electron microscopy (TEM) was applied for size and morphological analysis of nanoparticles. TEM result shows a spherical structure with an average size ranging from 24-35 nm for silver nanoparticles.

 Using fungi as sources of enzymes that can catalyze specific reactions conducing to inorganic nanoparticles, is being developed. Aspergillus flavus has a great potential in extracellular biosynthesis of silver nanoparticles. Since this fungus can grow on simple media quickly and adequately, it is cheaper to use it in silver nanoparticles biosynthesis than other methods. Extracellular biosynthesis of silver nanoparticles was carried out by adding 1mM silver nitrate to A. flavus cell filtrate. Nanoparticles production was confirmed by visual observation of color change in the cell filtrate and UV-vis spectrophotometry. More investigation was conducted using XRD, FTIR and TEM. The stability of nanoparticles and the effect of culture media and silver nitrate concentration on nanoparticles’ production were studied too. The color change of cell filtrate from pale to brown confirmed the extracellular production of silver nanoparticles. The absorption spectra indicated a peak at 420nm attributable to the sliver nanoparticles. X-ray diffraction showed crystalline nature of the biosynthesized nanoparticles. Characterization of sliver nanoparticles’ shape and size using TEM showed that they were spherical and 18.2 nm in diameter. These nanoparticles were stable for 11 months and FTIR demonstrated the presence of proteins as capping agents which lead to their stability. More silver nitrate caused more nanoparticles production and PDB was the best media in this process. Biosynthesized nanoparticles were crystalline in nature, small in size and monodispersed. Besides, they were very stable due to capping by fungal secreted proteins; this stability is reported for the first time in the world. The fungal-mediated green and ecofriendly approach towards the synthesis of nanoparticles can be used as an alternative to the more popular physical and chemical methods for the synthesis of nanoparticles

Heavy metals are environmentally sustainable and durable pollutants that have become a world problem. As microorganisms show high resistance to heavy metals and can purify the environment and produce nanoparticles, the present study was designed to produce copper nanoparticles from copper-resistant bacteria isolated from wastewater of two copper workshops in Isfahan.
In this cross-sectional study, wastewater samples were collected from two copper workshops in Isfahan. The physicochemical factors of the wastewater, the minimum inhibitory concentration of bacteria (MIC) to copper and their resistance to several antibiotics were investigated. Morphological, biochemical and molecular identification tests were carried out on samples. Then the biomass of copper-resistant bacteria was added to the copper sulfate pentahydrate stock (CuSO4.5H2O) and the results were evaluated by Ultraviolet-Visible
spectrophotometer (UV-VIS), X-ray diffraction (XRD) and Transient Electron Microscopy (TEM).
Among the studied bacteria, the Bacillus toyonensis strain NE2 with the MIC of 3.5 mM and Arthrobacteragilis NE1 with MIC of 4 mM from copper workshop 2 and Stenotrophomonas maltophilia strain 5633 with the MIC of 6 mM from copper workshop 1 were isolated. Among these isolates, only S. maltophilia strain 5633 was able to synthesize copper nanoparticles. Peaks created in the range of 250-430 nm confirmed the presence of Copper (Cu) and Copper Oxide (CuO) particles.
The findings of this study showed that the isolated bacteria could be a good candidate to remove copper from wastewater and to biosynthesize copper nanoparticle.

Iron magnetic nanoparticles have been widely studied for biological, medical as well as industrial applications. The physical and chemical synthesis methods currently used to produce nanoparticles cause environmental contamination. Certain bacteria are capable of synthesizing significant amounts of iron nanoparticles, quite in conformity with the principles of green chemistry. The objective of this study was to isolate and identify iron nanoparticle-producing bacteria from soils of Hormuz Island, Iran.
This cross-sectional study was carried out with soil sampling from the Hormuz Island. Following serial dilution, culturing and purification in a combined solid agar culture medium, biochemical and molecular tests were used to identify bacteria. The properties of nanoparticles produced by bacteria were studied using UV-Vis spectroscopy, X-ray crystallography (XRD) and scanning electron microscope (SEM).
The presence of Pseudomonas sp. was confirmed using biochemical characteristics, sequencing, and blasting the obtained sequences in NCBI database in the Hormuz Island soil. UV-Vis spectrometry and XRD graphs proved the presence of iron nanoparticles produced by bacteria. Furthermore, SEM images showed the size of nanoparticles as less than 50 nm.
The results of this study highlighted the adequacy of Pseudomonas isolated from the Hormuz Island soil in iron nanoparticle bio-synthesis as a cost-effective method, without any need for high energy expenditure. Therefore, the use of this bacterium as a useful biological source for large scale synthesis of iron nanoparticles is recommended through further studies.

Plants as stable and available sources to preparation of the biocompatible nano particles that have received much attention in recent years. The aim of this study were optimization and characterization of biosynthesis of gold nano particles (Au NPs) using leaf aqueous extract of Sambucus ebulus L. After preparing the extract, 2 ml of it, was added to 4 ml of HAuCl4.3H2O with concentration 1 mM, which reduced Au (III) ions to Au NPs, and quickly the color of solution changed to violet. In order to achieve Au NPs with a uniform shape and size, parameters affecting on synthesis such as: pH of the reaction, volume of plant extract, concentration of HAuCl4.3H2O solution, temperature and time of reaction were studied and optimized. All parameters were optimized using UV-Vis spectrophotometry. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were also employed to find characterization of the nanoparticles. Finally, the antibacterial properties of nanoparticles on 4 species of pathogenic bacteria such as: Staphylococcus aureus, Bacillus subtilis, E. coli and Salmonella enteritidis was evaluated by disc diffusion method and was reported as the diameter of inhibition zone. The results showed that the Au NPs showed a maximum absorbance at 534 nm. It was found that biosynthesized of Au NPs have spherical shape with a size between 11-17 nm and the gold nanoparticles have relatively good antibacterial activity against some bacteria.

Aim and Nowadays, using nanocarriers and targeted drug delivery have attracted more attention. Nanocarriers, especially gold nanoparticles have been presented as an appropriate choice for targeted drug delivery. Today, applying biological systems like microorganisms in synthesizing gold nanoparticles has been the focus of attention. Biosynthesis and aggregation of nanoparticles using clean biological systems which are biocompatible and non-toxic are known as green methods, especially compared with other chemical methods of synthesizing nanoparticles. In this study, Staphylococcus aureus was used for the biosynthesis of gold nanoparticles and the effects of their antimicrobial and cytotoxicity were examined. Perfectly spherical gold nanoparticles with an average size of 25 nm were synthesized. Techniques using different concentrations of gold nanoparticles were studied by MTT assay, and the concentration of more than half of the cells survived. MIC and MBC gold nanoparticles microbial tests for vancomycin-resistant Enterococcus faecium utilized for all concentrations of nanoparticles were dead bacteria. Using Gold Nanoparticles omitted vancomycin resistance in vancomycin-resistant Enterococci.

Nanotechnology involves technological research and development in spaces at the range of 1 to 100 nanometers, and in this technology, very small and atomic scale particles are created and handled. Plant extracts can be used as a green method for the synthesis of silver nanoparticles. In this study, the biosynthesis of silver nanoparticles was performed using extracts of sesame (Sesamum indicum) seeds. Silver nitrate was added to the seed extract, and then it was incubated at 30 ° C. The effects of three concentrations (1mM, 2mM and 3mM) of silver nitrate on the synthesis of silver nanoparticles were studied. The analyses of absorption spectroscopy UV-Visible, Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD) and Inductively Coupled Plasma (ICP) were conducted to assess the production of nanoparticles. UV-Visible spectroscopy analysis and the peak at 420 nm indicated the occurrence of nanoparticles in the extract. TEM image determined that the nanoparticles were spherical with average size of about 14 nm. XRD analysis showed the nano-crystals synthesized by the extract, and Inductively coupled Plasma (ICP) determined the conversion percentage of silver ion into silver nanoparticle as approximately 99.61 percent.

Allelopathic effects of aqueous extract of pagoda tree and creeping jenny on five crop plants including wheat (Triticum aestivum)، barley (Hordeum vuIgare)، corn (Zea mays)، millet (Pennisetum americanum) and chickpea (Cicer arietinum) were investigated in a series of experiments conducted at the faculty of Agriculture، SB University of Kerman، Iran. Experiments were based on RCBD with 3 replications in greenhouse condition and CRD in laboratory condition in which different concentrations of weed leaves extract including (0، 25، 50، 75 and 100% of a stock solution (10%W/V)) were applied on all crop plants at germination and seedling growth stages and different responses were measured. Results showed that the three way interaction effect of alkaloid × concentration × hybrid was significant on the traits in both greenhouse and laboratory. By increasing the concentration of alkaloid، inhibitory effect was also increased. The 100% concentration was most effect and control concentration was least effective. There was a significant difference between the two weeds in terms of allelopathic effects and creeping jenny reduced plants growth more compared to pagoda tree. However، all crops were significantly affected by allelopathic properties. It was concluded that pagoda tree and creeping jenny residues in the field had the potential of allelopathic effects on crop plants therefore should be removed from the field before planting.

Aim and In the past decade, science and technology has put enormous attention to produce nanoparticles. There are many methods to synthesize nanoparticles. Many techniques are inefficient in terms of material and energy consumption. Most chemical methods are hazardous chemicals for humans and the environment. For these reasons, there is a demand to produce nanoparticles with biological methods. This research is concentrated on extracellular biosynthesis of silver nanoparticles using non-pathogenic species of Leishmania. It was found that aqueous silver ions are reduced in solution when exposed to protozoa Leishmania, thereby leading to the formation of silver nanoparticles. The formation of silver nanoparticles was analyzed by uv-vis spectroscopy, microscopic images and elemental X-ray scattering spectra. In UV-Vis spectroscopy, the peak at 420 nm corresponds to the surface plasmon resonance of silver nanoparticles. The Atomic Force microscope (AFM) and Scanning electron microscope (SEM) images of nanoparticles in aqueous solution showed the production of silver nanoparticles (average particle size: 20 - 80 nm) by the protozoa. EDX spectra of silver nanoparticles excited by an electron beam, showed peaks for the elements of Ag. Leishmania protozoon is a green factory for the production of silver nanoparticles. Silver nanoparticles were in the range of 20–80 nm in dimensions. The use of this protozoon for silver nanoparticles synthesis offers the benefits of eco-friendliness, amenability, and timesaving for large-scale production.

Aim and Biosynthesis of nanoparticles using microorganisms is a noticeable method due to reduced use of energy and expenses as well as its environmental adaptation properties. It attracts many researchers as bio-method-based producing procedures were brought forth for discussion. Use of microorganisms in nanotechnology is one of the most important aspects of the discussion. Native Lactobacillus of Iran derived from some local dairy products was used in this study and exposed to Tio2 solution. Samples were delivered to the relevant labs to perform the experiments 72 hours after incubation. The Titanium nanoparticles were characterized by Scanning Electron Microscopy and Atomic Force Microscopy. Analysis of Titanium Nanoparticles with XRD was prepared. Nanoparticles Formation of Titanium in some Lactobacillus Plantarum strains was observed during the study. After some molecular mechanism deliberations, biosynthesis of nanoparticles using microorganisms and metal reduction via bacteria interpreted as a defensive process may be due to superoxide dismutase lack in some Lactobacillus Plantarum strains.