Biogenic Copper Oxide@rGO Nanocomposite for Decontamination of a Food Threat B. Cereus in a Rice Model

The main aim of the present study was to develop nanotechnology-based solutions for the management of a fungus, Phytophthora parasitica causing gummosis in citrus. Biogenic copper nanoparticles (CuONPs) were synthesized using two different biocontrol agents, Pseudomonas fluorescens and Trichoderma viride and characterized using different analytical techniques. Furthermore, in vitro (at the concentrations of 10, 15, 30, 50, 70, 100 and 150mg/L) and in vivo (at the concentration of 100mg/L) activities of these nanoparticles were evaluated for their antifungal efficacy against P. parasitica. The results obtained confirmed the synthesis of irregular-shaped CuONPs having a size in the range 40-100nm in case of P. fluorescens, whereas, spherical CuONPs in the size range 20-80 were recorded in case of T. viride. As far as the in vitro antifungal efficacies of both these CuONPs is concerned, the maximum percent growth inhibition was observed in case of CuONPs synthesized from T. viride compared to CuONPs from P. fluorescens. However, in case of in vivo antifungal efficacies, CuONPs synthesized from T. viride showed the activity significantly higher than the conventionally used Bordeaux mixture. It can be concluded that biosynthesized CuONPs can be effectively used as a potential fungicide against P. parasitica. The application of nanoparticles having antifungal activities can be used as alternative fungicides to the conventional chemical fungicides. It has the potential to revolutionize the existing management strategies available for plant pathogenic fungi.

In this study, biogenic copper and zinc oxide nanoparticles (G-ZnONPs and G-CuONPs) were synthesized by the green synthesis method using Malva parviflora L. (Millow) leaf extract and the obtained nanoparticles were characterized in detail with UV-Vis, FTIR, SEM, XRD. The antibacterial properties of the synthesized nanoparticles on gram-positive and gram-negative bacteria were investigated and it was found that the nanoparticles had high antimicrobial activity in the results of the experiments. With the obtained G-CuONPs, the synthesis of bis(indolyl)methanes with the “green” one-pot synthesis using microwave was achieved quickly and with high efficiency, and the thermal behavior of the obtained products was investigated.

Effect of long-term cadmium and copper intoxication on the efficiency of ampullate silk glands in false black widow Steatoda grossa (Theridiidae) spiders

Spiders play a crucial role in regulating insect populations in meadows, forests, and agricultural ecosystems.Although the importance of these carnivorous invertebrates in trophic chains of terrestrial ecosystems seems obvious, only a small number of research has been conducted under controlled laboratory conditions.This research allows for the correlation of levels of selected cellular parameters and the intensity of stressing factors, including metals.In anthropogenically polluted environments, the survival and effective role of spiders as essential predators, as well as concentrators of metals, rely on their ability to withstand excessive elements entering their bodies, primarily through the digestive tract [1].The sensitivity of spiders to metals may hinge on the metabolic condition of their hemocytes, involved in both humoral and cellular immunological reactions, and the state of midgut gland cells, where ingested metals from food can accumulate.[2].This study aims to verify whether and to what extent xenobiotic cadmium and biogenic copper, administered to Steatoda grossa (Theridiidae) females in a simple food chain model with sublethal concentrations for spiders (medium with 0.248 mM CdCl 2 or 0.234 mM CuSO 4 ) Drosophila hydei spider, can cause degenerative changes in hemocytes and midgut gland cells during chronic intoxication (individuals exposed to metals over two generations).Additionally, under in vitro and in vivo conditions, the study compared the hemocytes' ability to undergo oxygen burst reactions in response to receiving phorbol 12-myristate 13-acetate (PMA) as a synthetic immunostimulant, simulating conditions of possible contact with microorganisms [3].Both types of cells were assessed for quantitative (flow cytometry) and qualitative (Transmission Electron Microscopy) apoptotic, necrotic, or autophagic processes, as well as the percentage of cells with high-level reactive oxygen species (ROS+).This study confirmed that chronic exposure to cadmium and copper caused stronger degenerative changes in the hemocytes of S. grossa (Theridiidae) spiders compared to midgut gland cells.However, in midgut gland cells, the percentage of ROS+ cells exceeded that in hemocytes.In PMA-stimulated spiders, both types of cells exhibited strong prooxidative and degenerative effects from metals, significantly higher than in individuals exposed solely to metals.These results provide unique comparative data concerning the development of tolerance to metals present in food and aid in interpreting findings from field studies on these carnivorous invertebrates.

COVID-19 pandemic caused by coronavirus SARS-CoV-2 affected virtually all life aspects in most countries and nations. During 2020 around 100 mln of Earth inhabitants contracted this morbid infection and 2 mln people died thereafter. It is natural therefore that many pharmaceutical companies around the globe have joined into the race aimed at elaboration of prophylactic antiviral vaccines. However, the option can not be ruled out that parenteral vaccines to counter rapidly mutating pandemic coronavirus may be designed hastily, neglecting due tests of remote side effects, so that in the long run they risk to be expelled from the marked due to doubtful safety and efficiency.As a real alternative to traditional vaccination techniques the present mini-review has proposed application of intranasal adjuvant nano-vaccine. If necessary, this approach may be complemented with pharmacological inactivation of coronavirus under the impact of ribo-favipiravir, recombinant arginine deiminase, RNAse L or lactoferrin, as well as biogenic silver or copper nanoparticles - the preparations derived from up-to-date molecular biotechnological processes.

In this study, biogenic copper nanoparticles from metallic wastewater were examined for the synthesis of triazoles by a click reaction.

“Novel micronutrient laced biogenic copper oxide nanoparticles for treatment of diabetes in Wistar rats”

In this paper, we report a clean and green synthetic route of copper nanoparticles from copper salt using extract of basil (Ocimum tenuiflorum) flowers along with the study of their ability for selective amino acid detection. Using ultraviolet visible spectroscopy, the formation of biogenic copper nanoparticles in the medium was monitored at periodic intervals. Standard characterization techniques like high resolution transmission electron microscopy and X-ray diffraction were performed to reveal the microstructure and different phases of these extract-derived nanoparticles. Fourier transform infra-red curve detected the functional organic moieties involved in the capping and surface stabilization of the copper nanoparticles. Most significantly, we demonstrated the selective amino acid sensing ability of these bioengineered copper nanoparticles and discussed the possible mechanism behind this instant visual detection.

In this current research, biogenic Copper oxide (CuO) nanoparticles were successfully produced by the green method, i.e. microwave-assisted process using Andrographis paniculata as a source. Microwave-assisted biogenic CuO nanoparticles were investigated with various instrumental techniques. The micrographs of the FESEM and TEM showed that the size of particles is around 30 nm. In addition, the photocatalytic performance of CuO nanoparticles was conducted against the methylene blue (MB) dye in the presence of natural sunlight irradiation. Further, antimicrobial activities of the biogenic CuO nanoparticles were tested against foodborne pathogens. The CuO nanoparticles showed anti-cancer (A549: IC50:14.76 µg/mL) activity and they are biocompatible in nature. In addition, biogenic CuO nanoparticles can be applicable to toxic pollutant treatment and pharma drug applications.

Synthesis of nanoparticles is an extensive area for the scientists and plant-mediated biological synthesis is one of the green approaches attracted to the researchers. Objective: This experiment revealed the biological synthesis of copper nanoparticles (CuNPs) using aqueous extract mixture of two plants named bark extract of Moringa pterygo sperma (Sargavo) and root extract of Boerhavia diffusa (Saatodi/Punarnava). Method: Biomolecules present in the plants act as a reducing agent as well as a capping agent. In this reduction reaction, copper (II) metal reduced by biomolecules present in plants leads to the formation of CuNPs. Biosynthesized CuNPs characterized by spectral analysis (XRD, FTIR, UVvisible) and imaging microscopy (FEG-SEM with EDS and HR-TEM). Results: X-ray Diffraction spectroscopy revealed that crystalline CuNPs possess face centred cubic structure with an average size 2.20 nm. Fourier Transmission Infra-red spectroscopy showed that biomolecules like proteins are responsible for the reduction of metal ion and forming encapsulating layer on the metal ions (capping of CuNPs). Morphology of the CuNPs studied using Field Electron Gun Scanning Electron Microscopy (FEGSEM) and showed an irregular spherical shape. Elemental composition and purity of the CuNPs were analysed by Energy Dispersive Spectroscopy (EDS). High- Resolution Transmission Electron Microscopy revealed that the size of the CuNPs was 2 to10 nm. Antibacterial study of the biosynthesized CuNPs was examined against gram-positive (Bacillus subtilis) and gram-negative (Escherichia coli) bacteria using agar well diffusion method and CuNPs exhibited an excellent inhibition zone against the mentioned bacteria. Keywords: CuNPs, antibacterial study, biomolecules, reducing agents, Moringa pterygo sperma, Boerhavia diffusa.

We report an eco-friendly method for the synthesis of copper nanoparticles (CuNPs) using Citron juice (Citrus medica Linn.), which is nontoxic and cheap. The biogenic copper nanoparticles were characterized by UV-Vis spectrophotometer showing a typical resonance (SPR) at about 631 nm which is specific for CuNPs. Nanoparticles tracking analysis by NanoSight-LM20 showed the particles in the range of 10-60 nm with the concentration of 2.18 × 10(8) particles per ml. X-ray diffraction revealed the FCC nature of nanoparticles with an average size of 20 nm. The antimicrobial activity of CuNPs was determined by Kirby-Bauer disk diffusion method against some selected species of bacteria and plant pathogenic fungi. It was reported that the synthesized CuNPs demonstrated a significant inhibitory activity against Escherichia coli followed by Klebsiella pneumoniae, Pseudomonas aeruginosa, Propionibacterium acnes and Salmonella typhi. Among the plant pathogenic fungi tested, Fusarium culmorum was found to be most sensitive followed by F. oxysporum and F. graminearum. The novelty of this work is that for the first time citron juice was used for the synthesis of CuNPs.

Biogenic copper nanoparticles produced by using the Klebsiella pneumoniae strain NST2 curtailed salt stress effects in maize by modulating the cellular oxidative repair mechanisms

Nanoparticles (NPs) can be used in several ways in agriculture, including increasing production rates and improving nutritional values in plants. The present study aims to clarify how biogenic copper oxide nanoparticles (CuO NPs) applied by two routes of exposure (foliar spray and soil irrigation) affect the elemental uptake by lettuce. In vivo experiments using lettuce (n = 4) were performed with CuO NPs in comparison with copper salt (CuSO4), considering a final mass added of 20 mg of CuO per plant. The elemental composition of roots was mostly affected by the soil irrigation exposure for both Cu forms (NPs and salt). Neither Cu form added by soil irrigation was translocated to leaves. Copper concentration in leaves was mainly affected by foliar spray exposure for both Cu forms (NPs and salt). All Cu forms through foliar spray were sequestered in the leaves and no translocation to roots was observed. Foliar spray of CuO NPs caused no visual damage in leaves, resulted in less disturbance of elemental composition, and improved dry weight, number of leaves, CO2 assimilation, and the levels of K, Na, S, Ag, Cd, Cr, Cu, and Zn in leaves without causing significant changes in daily intake of most elements, except for Cu. Although Cu concentration increased in leaves by foliar spray of CuO NPs, it remained safe for consumption.

Sulfate-reducing bacteria (SRB) play a major role in the precipitation of metal sulfides in the environment. In this work, biogenic copper sulfide formation was examined in cultures of SRB and compared to chemically initiated Cu sulfide precipitation as a reference system. Mixed cultures of SRB were incubated at 22, 45, and 60°C in nutrient solutions that contained copper sulfate. Abiotic reference samples were produced by reacting uninoculated liquid media with Na2S solutions under otherwise identical conditions. Precipitates were collected anaerobically by centrifugation, frozen in liquid N2, and freeze-dried, followed by analysis using X-ray diffraction (XRD), X-ray fluorescence, and scanning electron microscopy. Covellite (CuS) was the only mineral found in the precipitates. Covellite was less crystalline in the biogenic precipitates than in the abiotic samples based on XRD peak widths and peak to background ratios. Poor crystallinity may be the result of slower precipitation rates in bacterial cultures as compared to the abiotic reference systems. Furthermore, bacterial cells may inhibit the nucleation steps that lead to crystal formation. Incubation at elevated temperatures improved the crystallinity of the biotic specimens.

The synthesis of biogenic nanoparticles from non-chemical resources has increased the drive toward understanding infection biology. Accordingly, we aimed to address the symbiotic antibiofilm effect of biogenic copper and zinc oxide nanoparticles with antimicrobials against multidrug resistant (MDR) pathogens. The minimum inhibitory concentration (MIC) of copper nanoparticles (CuNPs) and zinc oxide nanoparticles (ZnONPs) at the range from 2 to 128 µg/ml was calculated against Gram-positive and Gram-negative pathogenic bacteria using a broth dilution method. Both nanoparticles have prime antibacterial activity compared with standard antibiotics (excluding against P.aeruginosa MTCC 741). A qualitative assessment of biofilm formation and collegial effect was performed using a modified test tube and the microtiter plate-based method by measuring the optical density and time kill of nanoparticles. The results demonstrated efficient antibiofilm activity of CuNPs in its lowest concentration than ZnONPs and antibiotics itself. In addition, significant enhancing antibiofilm effect was also shown by CuNPs in the presence of third generation antibiotics against Gram-negative and Gram-positive bacteria. A scanning electron microscopy (SEM) analysis was used to investigate the effect of the nanoparticles on morphological changes of Staphylococcus aureus. Current data highlights, biogenic CuNPs and ZnONPs could be used as an adjuvant for antibiotics in the treatment of bacterial infections.