Fungicidal synergistic effect of biogenically synthesized zinc oxide and copper oxide nanoparticles against Alternaria citri causing citrus black rot disease.

Citrus black rot disease being caused by Alternaria citri is a major disease of citrus plants with 30-35% economic loss annually. Fungicides had not been effective in the control of this disease during last few decades. In the present study, antifungal role of green synthesized zinc oxide (ZnO) and copper oxide (CuO) nanoparticles (NPs) were studied against Alternaria citri. Alternaria citri was isolated from disease fruits samples and was identified by staining with lacto phenol cotton blue. Furthermore, CuO and ZnO NPs were synthesized by utilizing the lemon peels extract as the reducing and capping agent. Nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. From the XRD data, the calculated size of CuO NPs was to be 18 nm and ZnO NPs was16.8 nm using Scherrer equation. The SEM analyses revealed the surface morphology of all the metal oxide NPs synthesized were rounded, elongated and or spherical in the shape. The zone of inhibition was observed to be 50 ± 0.5 mm by CuO NPs, followed by 51.5 ± 0.5 mm by ZnO NPs and maximum zone of antifungal inhibition was observed to be 53 ± 0.6 mm by mix metal oxide NPs. The results of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the synthesized nanoparticles showed that at the certain concentrations (80 mg ml-1), these NPs were capable of inhibiting the fungal growth, whereas above that specified concentrations (100 mg ml-1), NPs completely inhibited the fungal growth. Based on these findings, the green synthesized NPs can be used as alternative to fungicide in order to control the citrus black rot disease.

Sardar M ，Ahmed W ，Al Ayoubi S ，Nisa S ，Bibi Y ，Sabir M ，Khan MM ，Ahmed W ，Qayyum A ... -  《-》

Antifungal Activity of Green and Chemically Synthesized ZnO Nanoparticles against Alternaria citri, the Causal Agent Citrus Black Rot.

Elshafie HS ，Osman A ，El-Saber MM ，Camele I ，Abbas E ... -  《-》

Antifungal activity of Zinc nitrate derived nano Zno fungicide synthesized from Trachyspermum ammi to control fruit rot disease of grapefruit.

Grapefruit (Citrus paradisi) is a widely grown citrus and its fruit is affected by a variety of biotic and abiotic stress. Keeping in view the hazardous effects of synthetic fungicides, the recent trend is shifting towards safer and eco-friendly control of fruit diseases. The present study was aimed to diagnose the fruit rot disease of grapefruit and its control by using zinc oxide green nanoparticles (ZnO NPs). Fruit rot symptoms were observed in various grapefruit growing sites of Pakistan. Diseased samples were collected, and the disease-causing pathogen was isolated. Following Koch's postulates, the isolated pathogen was identified as Rhizoctonia solani. For eco-friendly control of this disease, ZnO NPs were prepared in the seed extract of Trachyspermum ammi and characterized. Fourier transform infrared spectroscopy (FTIR) of these NPs described the presence of stabilizing and reducing compounds such as phenols, aldehyde and vinyl ether, especially thymol (phenol). X-ray diffraction (XRD) analysis revealed their crystalline nature and size (48.52 nm). Energy dispersive X-ray (EDX) analysis elaborated the presence of major elements in the samples, while scanning electron microscopy (SEM) confirmed the morphology of bio fabricated NPs. ZnO NPs exhibited very good anti-fungal activity and the most significant fungal growth inhibition was observed at 1.0 mg/ml concentration of green NPs, in vitro and in vivo. These findings described that the bioactive constituents of T. ammi seed extract can effectively reduce and stabilize ZnO NPs. It is a cost-effective method to successfully control the fruit rot disease of grapefruit.

Ali M ，Wang X ，Haroon U ，Chaudhary HJ ，Kamal A ，Ali Q ，Saleem MH ，Usman K ，Alatawi A ，Ali S ，Hussain Munis MF ... -  《-》

Green Synthesis of Copper Oxide Nanoparticles Using Aerva javanica Leaf Extract and Their Characterization and Investigation of In Vitro Antimicrobial Potential and Cytotoxic Activities.

The development of green technology is creating great interest for researchers towards low-cost and environmentally friendly methods for the synthesis of nanoparticles. Copper oxide nanoparticles (CuO-NPs) attracted many researchers due to their electric, catalytic, optical, textile, photonic, monofluid, and pharmacological activities that depend on the shape and size of the nanoparticles. This investigation aims copper oxide nanoparticles synthesis using Aerva javanica plant leaf extract. Characterization of copper oxide nanoparticles synthesized by green route was performed by three different techniques: X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, and Scanning Electron Microscopy (SEM). X-ray diffraction (XRD) reveals the crystalline morphology of CuO-NPs and the average crystal size obtained is 15 nm. SEM images showed the spherical nature of the particles and size is lying in the 15-23 nm range. FTIR analysis confirms the functional groups of active components present in the extract which are responsible for reducing and capping agents for the synthesis of CuO-NPs. The synthesized CuO-NPs were studied for their antimicrobial potential against different bacterial as well as fungal pathogens. The results indicated that CuO-NPs show maximum antimicrobial activities against all the selected bacterial and fungal pathogens. Antimicrobial activities of copper oxide nanoparticles were compared with standard drugs Norfloxacin and amphotericin B antibiotics. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of copper oxide nanoparticles were 128 μg/mL against all selected bacterial pathogens. MIC of fungus and minimum fungicidal concentration (MFC) of CuO-NPs were 160 μg/mL. Thus, CuO-NPs can be utilized as a broad-spectrum antimicrobial agent. The cytotoxic activity of the synthesized CuO-NPs suggested that toxicity was negligible at concentrations below 60 μg/mL.

Amin F ，Fozia ，Khattak B ，Alotaibi A ，Qasim M ，Ahmad I ，Ullah R ，Bourhia M ，Gul A ，Zahoor S ，Ahmad R ... -  《-》

Alpinia officinarum mediated copper oxide nanoparticles: synthesis and its antifungal activity against Colletotrichum gloeosporioides.

Green synthesis offers an environmentally friendly and cost-effective alternative for the synthesis of copper oxide nanoparticles (CuO NPs). In this study, the synthesis of CuO NPs was optimized by using copper sulfate (CuSO4) and the aqueous extract of Alpinia officinarum and its antifungal activity were investigated. The synthesized CuO NPs were characterized by UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), Fourier-transform infrared radiation spectroscopy (FT-IR), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), dynamic light scattering (DLS), and transmission electron microscopy (TEM). The results showed that the optimized conditions for the synthesis of CuO NPs were 1:2 ratio of extract and CuSO4 solution, pH 7, and 30 °C. The characteristic UV-vis peak of A. officinarum synthesized CuO NPs was at 264 nm. The synthesized CuO NPs had high crystallinity and purity and were spherical in morphology with the mean size of 46.40 nm. The synthesized CuO NPs reduced the fungal growth of Colletotrichum gloeosporioides in a dose-dependent manner. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the CuO NPs were 125 μg·mL-1 and 500 μg·mL-1, respectively. The antifungal activity of CuO NPs may be attributed to its ability to deform the structure of fungal hyphae, induce excessive reactive oxygen species accumulation and lipid peroxidation in fungi, disrupt the mycelium cell membrane, and result cellular leakage.

Hu C ，Zhu W ，Lu Y ，Ren Y ，Gu J ，Song Y ，He J ... -  《-》