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

This study aimed to isolate and identify bacteria from soils contaminated with copper and have access to a capable bacterial strain for producing copper nanoparticles (CuNPs). The present study showed the extracellular production of copper nanoparticles using strain Ta-31. The effect of various factors such as substrate, supernatant volume, enzyme inducer, and electron donor was investigated on the production process. The properties of synthesized nanoparticles were identified by using UV-Vis, FTIR, XRD, SEM, and EDS analysis. Moreover, the growth curve of strain Ta-31 was plotted in the presence and absence of an enzyme inducer (concentration of 0.1 mM copper sulfate). After the phylogenetic analysis, 16S rDNA gene sequences were determined, and their phylogenetic tree of the selected strain was plotted. The results showed that the best conditions for producing CuNPs, glucose 1% as an electron donor, 2 mM copper sulfate, and 20 ml supernatant had the best production. Strain Ta-31 arrived at the end of the log phase and the beginning of the stationary phase after 15 h. CuNPs were spherical and irregular, and the size of CuNPs was more in the range of 30-40 nm. According to the results, strain Ta-31 belonged to Staphylococcus pasteuri sp. with 99.88% similarity.

Copper nanoparticles (CuNPs) are used in various industries, including pharmaceutical and biomedical sciences, agricultural and food chemistry, electronics and environmental applications, due to their novel optical, chemical, photoelectrochemical, and electronic properties as well as antimicrobial activities. The aim of the present study was to evaluate the ability of endophytic bacteria to synthesize CuNPs.

Eighteen endophytic bacteria (CN1-CN18) were isolated from the root and crown rot of the bean. The agar dilution method was used to determe the intrinsic tolerance of endophytic bacterial isolates to copper ions. Characterization of CuNPs was performed using different methods including ultraviolet–visible spectroscopy (UV–Vis), field emission scanning electron microscope (FE-SEM), Fourier transform infrared (FTIR), X-ray energy diffraction spectroscopy (EDS), and powder X-ray diffraction (XRD). The antimicrobial activity of the copper nanoparticles was investigated by the agar well diffusion method.

The results of the study indicated that isolate CN10 was able to reduce CuCl2 to CuNPs. Based on the obtained phenotypic data and 16s rDNA sequence analysis (similarity above 99%), the isolate was identified as Pseudomonas grimontii. Additionally, spherical CuNPs with an average size of 24.8 nm were synthesized by resting cells of strain CN10 under 3 mM of copper chloride, pH 7.0, agitation 100 rpm, and 96 hours of incubation. The results of antimicrobial tests showed that the produced CuNPs exhibited the highest inhibitory effects on Xanthomonas campestris (19.2 mm) and the lowest inhibitory effects on Staphylococcus aureus (9.4 mm).

The current study is the first report on the synthesis of CuNPs using a resting cell of Pseudomonas grimontii. The results suggested the synthesis of CuNPs using endophytic bacteria as a promising tool for the production of CuNPs in a controlled shape and size.

Nanotechnology as a modern science is rapidly expanding which can influx many biological aspects due to large extent. For this reason, concerns about the risks and consequences of this technology are rising in environment and especially in water resources. The purpose of this study is to investigate the effect of waterborn Cuo Nanoparticles on Oncorhynchus mykiss gill tissue, to detect a suitable biomarker for noticing Copper in Water Resources. Samples weighted 18±3 gr and exposure to Cuo Nanoparticels for a week with 25, 30, 50 and 100 ml/g doses. Physicochemical properties of water were 14±2 Cº temperature, 8-8.5 pH and 270 mg/l Caco3. At the end of 7 days, 9 fish were catch randomly from each treatment and second gill from left side of fish were removed for histological review. Hyperplasia, Oedema, Epithelial lifting in secondary lamella, lamellar aneurysm and Leukocyte infiltration was observed in gill tissues. In addition, the damage was determined at various concentrations of copper nanoparticles. Result showed that Cuo Nanoparticles, as copper ions, have significant adverse effects on gill tissues of O. mykiss and gills can be a suitable biomarker for copper in water resources. However, comparison of the extent and severity of injury stated that copper nanoparticles cause much less injury than copper ions.