جستجوی مقالات مرتبط با کلیدواژه « Biosynthesis » 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.

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.

Magnetic nanoparticles have various biomedical applications such as cell therapy, tissue repair, drug delivery, and magnetic resonance imaging (MRI) due to their unique physical, chemical, thermal, and mechanical characteristics as well as their suitable surface properties. The present study aimed to synthesize magnetic Fe3O4 nanoparticles (NPs) using the interaction of cell-free extracts of endophytic bacterial isolates with Fe2O3 as the precursor of NPs.

In this study, the extracellular synthesis of Fe3O4 NPs was accomplished by the cell-free extract (CFE) strategy. Characterization of Fe3O4 NPs was performed using different methods, including ultraviolet–visible spectroscopy (UV–Vis), field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR).

The obtained results of the study showed that the precursor Fe2O3 could be transformed into Fe3O4 NPs with the endophytic strain BR06. Phylogenetic analysis indicated that the isolated strainBR06 belonged to the genus Bacillus, and shared the highest sequence similarity with B. siamensis (MT052693). The Fe3O4 NPs with average diameters of 34 nm and cauliflower shape were synthesized by the endophytic strain BR06 in the biotransformation medium containing 5 mM Fe2O3 after 24 h incubation time. Electron microscopy and the associated spectroscopic analyses confirmed the formation of Fe3O4 NPs.

In the present study, for the first time, the biosynthesis of extracellular magnetite NPs was described using B. siamensis under the cell-free extract strategy.

The biosynthesis of nanoparticles (NPs) has been proposed due to its fast, clean, safe, and cost-effective production and being efficient alternative to conventional physicochemical methods. This study aimed to isolate and identify aquatic yeast strains for their potential to form Zinc oxide nanoparticles (ZnONPs). A yeast strain, NS02, with high tolerance against zinc ion (5.25 mM) was isolated using the enrichment technique and was selected as efficient candidate for the biosynthesis of ZnONPs under cell-free extract (CFE) strategy. The preliminary evaluation on the formation of ZnONPs was performed by visual observation and UV-visible absorption spectra of the biosynthesized ZnONPs. The morphology, size and elemental distribution of the nanoparticles were determined by Field emission scanning electron microscopy (FESEM) equipped with energy-dispersive X-ray (EDX). X-ray diffractometer (XRD) was used to identify the crystalline phase of the ZnONPs. Antibacterial activity of ZnONPs against pathogenic bacteria isolated from the clinical specimens was investigated using agar well diffusion method. The isolate NS02 was characterized based on their morphological properties and amplification the ITS-5.8S-ITS2 rDNA regions. The present study pioneered the capabilities of the native aquatic strain Rhodotorula pacifica for the extracellular synthesis of ZnONPs with CFE strategy. The biosynthesized ZnONPs had a growth inhibitory effect all tested clinical isolates due to their nanometric size and well-defined dispersity. This investigation is attempted to indicate the novel microbial sources of aquatic yeasts as biological plant in the synthesis of ZnONPs with antimicrobial activity under cell-free extract strategy.

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.

Diatoms biosilica shell, frustule, is substitute biostructures to mesoporous silica particles, which possesses their wide surfaces, nano-diameter porosity, mechanical strength, and thermal stability, optical capabilities, and the ability to bind to biomolecules can be used in biosensing applications. In this study, diatom species called Chaetoceros muelleri, was used for the fabrication of the Fe2O3-Au-Biosilica magnetic package. After micro-algae cultivation, the synthesis of gold nanoparticles (AuNPs) on silica walls was carried out using the bio-synthesis method, which evaluations have demonstrated the continuous formation of spherical AuNPs on the walls and its surfaces. After this step, the magnetic iron oxide nanoparticles were attached to the silica surface of the diatom, this, in turn, leads to system guiding using a magnetic field. Surface modification of diatoms magnetic complex, by using the APTES, allowed the attachment of fluorescence Rhodamine and the Herceptin antibody (Trastuzumab) to the structure. As well as the attachment of the fabricated system to target cells (SKBR3) was confirmed by fluorescence microscopic analysis. The results of this study indicate the ability and specificity of the diatom silicone shell as a "multipurpose" package for diagnostic and therapeutic activities.