Antifungal Potential of Green Synthesized Magnetite Nanoparticles Black Coffee-Magnetite Nanoparticles Against Wilt Infection by Ameliorating Enzymatic Activity and Gene Expression in Solanum lycopersicum L

Proteomic analysis of Trichoderma harzianum secretome and their role in the biosynthesis of zinc/iron oxide nanoparticles

The fungal green synthesis of nanoparticles (NPs) has gained great interest since it is a cost-effective and easy handling method. The process is simple because fungi secrete metabolites and proteins capable of reducing metal salts in aqueous solution, however the mechanism remains largely unknown. The aim of this study was to analyze the secretome of a Trichoderma harzianum strain during the mycobiosynthesis process of zinc and iron nanoparticles. Different profiles of proteins secreted by the fungus grown in the culture media or in the aqueous filtrate were observed through SDS‒PAGE and LC‒MS/MS analysis identifying 99 and 304 proteins, respectively. Particularly, in the aqueous filtrate proteins of metabolic processes and stress response mainly oxidoreductases, were identified. Successfully, ZnO and FeO NPs were synthesized and characterized by transmission electron microscopy, energy dispersive X-ray spectroscopy, dynamic light scattering, thermogravimetric, and FTIR analysis. FTIR revealed organic compounds in nanoparticles acting as probably capping agents. This research is the first report in which a proteomic analysis identifies multiple enzymes involved in the biogenic process of NP biosynthesis from T. harzianum, and its role is clearly demonstrated by the formation of zincite and magnetite nanoparticles.

Comparative study on the biosynthesis of magnetite nanoparticles using Aspergillus elegans extract and their efficacy in dye degradation versus commercial magnetite nanoparticles

This study compares magnetite (Fe3O4) nanoparticles synthesized using Aspergillus elegans extract versus commercially available magnetite nanoparticles, focusing on their efficacy in dye degradation. The biosynthesis of Fe3O4 nanoparticles using fungal extracts offers a sustainable and eco-friendly alternative to conventional chemical methods. The nanoparticles were characterized using various techniques, including UV-Vis spectroscopy, XRD, FTIR, SEM, TEM, DLS, zeta potential, and VSM analysis, to assess their structural, morphological, and magnetic properties. Results showed that fungus-mediated Fe3O4 nanoparticles were smaller, with an average size of 19.2 nm, and exhibited better crystallinity, surface functionalization, and colloidal stability than their commercial counterparts, which had an average size of 60 nm. Additionally, the fungal nanoparticles displayed superior magnetic properties with a saturation magnetization of 50 emu/g compared to 36 emu/g for commercial Fe3O4. The dye degradation potential of the nanoparticles was tested using methyl violet, methyl orange, and rose bengal dyes. Fungus-mediated Fe3O4 nanoparticles demonstrated higher dye removal efficiency than commercial Fe3O4, indicating enhanced catalytic activity due to their smaller size and larger surface area. This study highlights the potential of myco-synthesized Fe3O4 nanoparticles as effective agents for environmental remediation, particularly in removing of hazardous synthetic dyes from wastewater.

Advancements in the nanodelivery of azole-based fungicides to control oil palm pathogenic fungi

The cultivation of oil palms is of great importance in the global agricultural industry due to its role as a primary source of vegetable oil with a wide range of applications. However, the sustainability of this industry is threatened by the presence of pathogenic fungi, particularly Ganoderma spp., which cause detrimental oil palm disease known as basal stem rot (BSR). This unfavorable condition eventually leads to significant productivity losses in the harvest, with reported yield reductions of 50-80 % in severely affected plantations. Azole-based fungicides offer potential solutions to control BSR, but their efficacy is hampered by limited solubility, penetration, distribution, and bioavailability. Recent advances in nanotechnology have paved the way for the development of nanosized delivery systems. These systems enable effective fungicide delivery to target pathogens and enhance the bioavailability of azole fungicides while minimising environmental and human health risks. In field trials, the application of azole-based nanofungicides resulted in up to 75 % reduction in disease incidence compared to conventional fungicide treatments. These innovations offer opportunities for the development of sustainable agricultural practices. This review highlights the importance of oil palm cultivation concerning the ongoing challenges posed by pathogenic fungi and examines the potential of azole-based fungicides for disease control. It also reviews recent advances in nanotechnology for fungicide delivery, explores the mechanisms behind these nanodelivery systems, and emphasises the opportunities and challenges associated with azole-based nanofungicides. Hence, this review provides valuable insights for future nanofungicide development in effective oil palm disease control.

Optimizing the green synthesis of antibacterial TiO2 - anatase phase nanoparticles derived from spinach leaf extract

Titanium dioxide nanoparticles, renowned for their abundance, non-toxicity, and stability, have emerged as indispensable components in various fields such as air purification, healthcare, and industrial processes. Their applications as photocatalysts and antibacterial agents are particularly prominent. The synthesis methods significantly influence the properties and subsequent applications of these nanoparticles. While several techniques exist, the biological approach using plant extracts offers advantages such as simplicity, biocompatibility, and cost-effectiveness. This study focused on the green synthesis of titanium dioxide nanoparticles utilizing spinach leaf extract. Within the scope of this investigation, the green synthesis of titanium dioxide nanoparticles through spinach leaf extract were synthesized and optimized, followed by a comprehensive examination of their morphological, structural, and chemical attributes with UV-visible spectroscopy, FTIR spectroscopy, XRD, FESEM, and EDX. The minimum inhibitory concentration (MIC) against E. coli and S. aureus was determined to evaluate their antibacterial potential. Optimal synthesis conditions were identified at 50 °C, using a 1/30 concentration and 20 ml of spinach leaf extract. Spherical anatase nanoparticles, ranging from 10 to 40 nm, were produced under these conditions. The change in the color of the extract, absorption at 247 nm, change and increase of the peak at 800 - 400 wavelengths, and the maximum intensity of X-ray diffraction at the angle of 25.367 with the crystal plane 101 were indications of the synthesis of these nanoparticles. Notably, the synthesized nanoparticles exhibited antibacterial activity with MIC values of 0.5 mg/ml against E. coli and 2 mg/ml against S. aureus. This research presents a novel, eco-friendly approach to synthesizing titanium dioxide nanoparticles with promising antibacterial properties.

Green synthesis of Superparamagnetic Iron Oxide and Silver Nanoparticles in Satureja hortensis Leave Extract: Evaluation of Antifungal Effects on Botryosphaeriaceae Species

In recent years, green synthesis methods of metallic nanoparticles (MNPs) have been attractive because of the more facile, cheaper, and appropriate features associated with biomolecules in MNPs biosynthesis. This research represented an easy, fast, and environmentally friendly method to biosynthesis of superparamagnetic iron oxide nanoparticles (SPIONPs) and silver nanoparticles (AgNPs) by the Satureja hortensis leaf extract as stabilizer and reducer. The SPIONPs synthesized in co-precipitation method. The biosynthesized SPIONPs and AgNPs were studied their antifungal effects against three Botryosphaeriaceae plant pathogens, Botryosphaeria dothidea, Diplodia seriata, and Neofusicoccum parvum. UV-visible spectra (UV-Vis), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (Fe-SEM), energy-dispersive X-ray spectroscopy (EDX), and vibrating-sample magnetometer (VSM) analyses were used to evaluate the physicochemical properties and verify the formation of green synthesized SPIONPs and AgNPs. UV-Vis spectra revealed absorption peaks at 243 and 448 nm for SPIONs and 436 nm for AgNPs, respectively. Microscopic and XRD analysis showed that SPIONPs and AgNPs was found spherical in shape with an average particle size of SPIONPs and AgNPs 10 and 12 nm, respectively. The antifungal test against Botryosphaeriaceae species showed that SPIONPs and AgNPs possess antifungal properties against B. dothidea, D. seriata, and N. parvum. However, AgNPs exhibits greater antifungal activity than SPIONPs. The results of the cytotoxicity tests of SPIONs and AgNPs on the MCF-7 cell line showed that AgNPs was significantly more cytotoxic towards the MCF-7 cell line, whereas no significant cytotoxic effect was recorded by SPIONs. Therefore, these biosynthesized MNPs could be substituted for toxic fungicides that are extensively applied in agriculture and contribute to environmental health and food safety.

Nanoparticles and Chemical Inducers: A Sustainable Shield against Onion White Rot

This study investigated the effectiveness of nanoparticles and chemical inducers in managing onion white rot caused by Sclerotium cepivorum. The pathogen severely threatens onion cultivation, resulting in significant yield losses and economic setbacks. Traditional fungicides, though effective, raise environmental concerns, prompting a shift toward eco-friendly alternatives. In this study, four S. cepivorum isolates were utilized, each exhibiting varying degrees of pathogenicity, with the third isolate from Abu-Hamad demonstrating the highest potency. During the in vitro studies, three nanoparticles (NPs) were investigated, including Fe3O4 NPs, Cu NPs, and ZnO NPs, which demonstrated the potential to inhibit mycelial growth, with salicylic acid and Fe3O4 NPs exhibiting synergistic effects. In vivo, these nanoparticles reduced the disease incidence and severity, with Fe3O4 NPs at 1000-1400 ppm resulting in 65.0-80.0% incidence and 80.0-90.0% severity. ZnO NPs had the most positive impact on the chlorophyll content, while Cu NPs had minimal effects. At 1000 ppm, Fe3O4 NPs had variable effects on the phenolic compounds (total: 6.28, free: 4.81, related: 2.59), while ZnO NPs caused minor fluctuations (total: 3.60, free: 1.82, related: 1.73). For the chemical inducers, salicylic acid reduced the disease (10.0% incidence, 25.0% to 10.0% severity) and promoted growth, and it elevated the chlorophyll values and enhanced the phenolic compounds in infected onions. Potassium phosphate dibasic (PDP) had mixed effects, and ascorbic acid showed limited efficacy toward disease reduction. However, PDP at 1400 ppm and ascorbic acid at 1000 ppm elevated the chlorophyll values and enhanced the phenolic compounds. Furthermore, this study extended to traditional fungicides, highlighting their inhibitory effects on S. cepivorum. This research provides a comprehensive comparative analysis of these approaches, emphasizing their potential in eco-friendly onion white rot management.

Inorganic Fe-O and Fe-S oxidoreductases: paradigms for prebiotic chemistry and the evolution of enzymatic activity in biology

Oxidoreductases play crucial roles in electron transfer during biological redox reactions. These reactions are not exclusive to protein-based biocatalysts; nano-size (<100 nm), fine-grained inorganic colloids, such as iron oxides and sulfides, also participate. These nanocolloids exhibit intrinsic redox activity and possess direct electron transfer capacities comparable to their biological counterparts. The unique metal ion architecture of these nanocolloids, including electron configurations, coordination environment, electron conductivity, and the ability to promote spontaneous electron hopping, contributes to their transfer capabilities. Nano-size inorganic colloids are believed to be among the earliest 'oxidoreductases' to have 'evolved' on early Earth, playing critical roles in biological systems. Representing a distinct type of biocatalysts alongside metalloproteins, these nanoparticles offer an early alternative to protein-based oxidoreductase activity. While the roles of inorganic nano-sized catalysts in current Earth ecosystems are intuitively significant, they remain poorly understood and underestimated. Their contribution to chemical reactions and biogeochemical cycles likely helped shape and maintain the balance of our planet's ecosystems. However, their potential applications in biomedical, agricultural, and environmental protection sectors have not been fully explored or exploited. This review examines the structure, properties, and mechanisms of such catalysts from a material's evolutionary standpoint, aiming to raise awareness of their potential to provide innovative solutions to some of Earth's sustainability challenges.

Biofilm-associated genes as potential molecular targets of nano-Fe3O4 in Candida albicans

BACKGROUND

There are few effective treatments for Candida biofilm-associated infections. The present study demonstrated changes in the expression of biofilm-associated genes in Candida albicans treated with magnetic iron oxide nanoparticles (denoted as nano-Fe₃O₄).

METHODS

Nano-Fe₃O₄ was biologically synthesized using Bacillus licheniformis, Bacillus cereus, and Fusarium oxysporum. Additionally, the biologically synthesized nano-Fe₃O₄ was characterized by visual observation; ultraviolet-visible spectroscopy, scanning electron microscopy, X-ray diffraction spectroscopy, and Fourier transform infrared spectroscopy. The biologically synthesized nano-Fe₃O₄ was tested for growth and biofilm formation in C. albicans. Furthermore, quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was used to study the inhibition of biofilm-associated genes in C. albicans treated with nano-Fe₃O₄.

RESULTS

The production of biologically synthesized nano-Fe₃O₄ was confirmed using extensive characterization methods. The nano-Fe₃O₄ inhibited growth and biofilm formation. Nano-Fe₃O₄ exhibited growth inhibition with minimum inhibition concentrations (MICs) of 50 to 200 μg mL^-1. The anti-biofilm effects of nano-Fe₃O₄ were shown by 2,3-bis (2-methoxy-4-nitro-5 sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide (XTT) reduction assay, crystal violet staining, and light field microscopy. The gene expression results showed that the downregulation of BCR1, ALS1, ALS3, HWP1, and ECE1 genes inhibited the biofilm formation in C. albicans. ALS1 reduction was greater than others, with downregulation of 1375.83-, 1178.71-, and 768.47-fold at 2 × MIC, 1 × MIC, and ½ × MIC of nano-Fe₃O₄, respectively.

CONCLUSION

Biofilm-associated genes as potential molecular targets of nano-Fe₃O₄ in C. albicans may be an effective novel treatment strategy for biofilm-associated infections.