Green synthesis of silver nanoparticles from Mahonia fortunei extracts and characterization of its inhibitory effect on Chinese cabbage soft rot pathogen

Combat phytopathogenic bacteria employing Argirium-SUNCs: limits and perspectives

Bacterial plant diseases are difficult to control as the durability of deployed control measures is thwarted by continuous and rapid changing of bacterial populations. Although application of copper compounds to plants is the most widespread and inexpensive control measure, it is often partially efficacious for the frequent appearance of copper-resistant bacterial strains and it is raising concerns for the harmful effects of copper on environment and human health. Consequently, European Community included copper compounds in the list of substances candidates for substitution. Nanotechnologies and the application of nanoparticles seem to respond to the need to find new very effective and durable measures. We believe that Argirium-SUNCs®, silver ultra nanoclusters with an average size of 1.79 nm and characterized by rare oxidative states (Ag2+/3+), represent a valid candidate as a nano-bactericide in the control of plant bacterial diseases. Respect to the many silver nanoparticles described in the literature, Argirium-SUNCs have many strengths due to the reproducibility of the synthesis method, the purity and the stability of the preparation, the very strong (less than 1 ppm) antimicrobial, and anti-biofilm activities. In this mini-review, we provide information on this nanomaterial and on the possible application in agriculture. KEY POINTS: • Argirium-SUNCs have strong antimicrobial activities against phytopathogenic bacteria. • Argirium-SUNCs are a possible plant protection product. • Argirium-SUNCs protect tomato plants against bacterial speck disease.

Green synthesis of metal nanoparticles and study their anti-pathogenic properties against pathogens effect on plants and animals

According to an estimate, 30% to 40%, of global fruit are wasted, leading to post harvest losses and contributing to economic losses ranging from $10 to $100 billion worldwide. Among, all fruits the discarded portion of oranges is around 20%. A novel and value addition approach to utilize the orange peels is in nanoscience. In the present study, a synthesis approach was conducted to prepare the metallic nanoparticles (copper and silver); by utilizing food waste (Citrus plant peels) as bioactive reductants. In addition, the Citrus sinensis extracts showed the reducing activity against metallic salts copper chloride and silver nitrate to form Cu-NPs (copper nanoparticles) and Ag-NPs (Silver nanoparticles). The in vitro potential of both types of prepared nanoparticles was examined against plant pathogenic bacteria Erwinia carotovora (Pectobacterium carotovorum) and pathogens effect on human health Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Moreover, the in vivo antagonistic potential of both types of prepared nanoparticles was examined by their interaction with against plant (potato slices). Furthermore, additional antipathogenic (antiviral and antifungal) properties were also examined. The statistical analysis was done to explain the level of significance and antipathogenic effectiveness among synthesized Ag-NPs and Cu-NPs. The surface morphology, elemental description and size of particles were analyzed by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy and zeta sizer (in addition polydispersity index and zeta potential). The justification for the preparation of particles was done by UV-Vis Spectroscopy (excitation peaks at 339 nm for copper and 415 nm for silver) and crystalline nature was observed by X-ray diffraction. Hence, the prepared particles are quite effective against soft rot pathogens in plants and can also be used effectively in some other multifunctional applications such as bioactive sport wear, surgical gowns, bioactive bandages and wrist or knee compression bandages, etc.

Biosynthesis, characterization, and antifungal activity of plant-mediated silver nanoparticles using Cnidium monnieri fruit extract

The present study describes a novel method for green synthesis of silver nanoparticles using Cnidium monnieri (CM-AgNPs). Cnidium monnieri fruit is an excellent anti tinea drug that can be used externally to treat superficial fungal infections in the human body. The aqueous ethanolic extract of Cnidium monnieri fruit was prepared and employed in the synthesis of stable silver nanoparticles via biological reduction method. The synthesis conditions of CM-AgNPs was systematically optimized using Box-Behnken design. CM-AgNPs were well characterized by UV-spectroscopy and X-ray powder diffraction (XRD), and it was confirmed that the synthesized particles were AgNPs. The possible functional groups required for the reduction and stabilization of CM-AgNPs in the extract were identified through FTIR spectrum. The size of CM-AgNPs structure was confirmed to be approximately 44.6 nm in polydisperse spherical shape through scanning electron microscopy (SEM), transmission electron microscopy (TEM), and laser dynamic light scattering (DLS). Further, the minimum inhibitory concentration 90% (MIC90) ratios values of Cm-AgNPs against Trichophyton rubrum (7 d), T. mentagrophytes (7 d) and Candida albicans (24 h) were 3.125, 3.125, and 0.78125 μg/mL, respectively, determined by the broth micro dilution method. Finally, the result was concluded that the synthesized AgNPs could be further evaluated in large scale as a potential human topical antifungal agent.