Production of silver nanoparticles using yeasts and evaluation of their antifungal activity against phytopathogenic fungi

In the present study, silver nanoparticles were synthesized by chemical reduction method route into the lamellar space of bentonite (Ag/CTS/Bentonite). Silver nitrate (AgNO3) was taken as a metal precursor, sodium borohydride (NaBH4) as a reducing agent, reduction of Ag+ ions and the subsequent formation of Ag nanoparticles, chitosan as a natural polymeric stabilizer and was sticked silver nanoparticles to the surface of bentonite particles, respectively. Manipulating the size and shape of Ag/CTS/Bentonite nanomaterial was characterized using transmission electron microscopy (TEM), spherical silver nanoparticles, as depicted by TEM, were found to have a wide particle size distribution from 5 nm to 90 nm. Meanwhile, the X-Ray flourescence (XRF) spectrum indicated the presence of silver on bentonite particles. Antifungal activity of the synthesized Ag/CTS/Bentonite nanomaterial was investigated against crop pathogenic fungi (Fusarium oxysporium (F. oxysporium) and Rhizoctonia solani (R. solani)) isolated from infected soybean plant in Bac Ninh province by the Plant Protection Research Institute. The assessment of fungicidal activity of the Ag/CTS/Bentonite nanomaterial showed that this product exhibited strong antifungal activity towards soybean pathogenic fungi. At highest nanosilver concentration of the Ag/CTS/Bentonite nanocomposite (400 ppm) sclerotial germination of F. oxysporum was almost inhibited, after 7 days the inhibition effect on sclerotial germination attained 66.70%. For the case of R. solani, after 2 days at 400 ppm silver nanoparticles concentration the inhibition effect on sclerotial germination attained 92.82%. The obtained results suggested that the synthesized Ag/CTS/Bentonite nanomaterial acts as an effective antifungal agent. Thus, it could be used in developing novel antifungal agents for potential applications in agriculture.

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Potential antifungal effects of silver nanoparticles (AgNPs) of different sizes against phytopathogenic Fusarium oxysporum f. sp. radicis-lycopersici (FORL) strains

SN Applied Sciences ◽

10.1007/s42452-021-04524-5 ◽

2021 ◽

Vol 3 (4) ◽

Author(s):

Ilgin Akpinar ◽

Muammer Unal ◽

Taner Sar

Keyword(s):

Silver Nanoparticles ◽

Fusarium Oxysporum ◽

Antifungal Agents ◽

New Technology ◽

Economic Loss ◽

Phytopathogenic Fungi ◽

Growth Media ◽

Mycelium Growth ◽

Antifungal Effects ◽

Critical Problems

AbstractFusarium species are the primary fungal pathogen affecting agricultural foodstuffs both in crop yield and economic loss. Due to these problems, control of phytopathogenic fungi has become one of the critical problems around the World. Nanotechnology is a new technology with potential in many fields, including agriculture. This study focused on determining potential effects of silver nanoparticles (AgNPs) with different nanosizes (3, 5, 8 and 10 nm) and at different concentrations (12.5–100 ppm) against phytopathogenic Fusarium oxysporum f. sp. radicis-lycopersici (FORL) strains. The maximum antifungal activity was achieved by decreasing nanosize and increasing concentration of AgNPs. Mycelium growth abilities were decreased about 50%, 75% and 90% by AgNPs treatment with 3 nm sizes at 25 ppm, 37.5 ppm and 50 ppm concentrations, respectively. The productivity of fungal biomass in the liquid growth media was found to be too limited at the 25–37.5 ppm of AgNPs concentrations with all sizes. In addition, both septation number and dimensions of micro- and macroconidia were found to be gradually decreased with the application of silver nanoparticles. This work showed that the low concentration of AgNPs could be used as potential antifungal agents and applied for control of phytopathogens.

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Antifungal Activity of Chemical Constituents from Piper pesaresanum C. DC. and Derivatives against Phytopathogen Fungi of Cocoa

Molecules ◽

10.3390/molecules26113256 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3256

Author(s):

Luis C. Chitiva-Chitiva ◽

Cristóbal Ladino-Vargas ◽

Luis E. Cuca-Suárez ◽

Juliet A. Prieto-Rodríguez ◽

Oscar J. Patiño-Ladino

Keyword(s):

Antifungal Activity ◽

Benzoic Acid ◽

Chemical Constituents ◽

Chemical Study ◽

Positive Control ◽

Positive Influence ◽

Phytopathogenic Fungi ◽

Phytochemical Study ◽

Benzoic Acid Derivatives ◽

First Time

In this study, the antifungal potential of chemical constituents from Piper pesaresanum and some synthesized derivatives was determined against three phytopathogenic fungi associated with the cocoa crop. The methodology included the phytochemical study on the aerial part of P. pesaresanum, the synthesis of some derivatives and the evaluation of the antifungal activity against the fungi Moniliophthora roreri, Fusarium solani and Phytophthora sp. The chemical study allowed the isolation of three benzoic acid derivatives (1–3), one dihydrochalcone (4) and a mixture of sterols (5–7). Seven derivatives (8–14) were synthesized from the main constituents, of which compounds 9, 10, 12 and 14 are reported for the first time. Benzoic acid derivatives showed strong antifungal activity against M. roreri, of which 11 (3.0 ± 0.8 µM) was the most active compound with an IC50 lower compared with positive control Mancozeb® (4.9 ± 0.4 µM). Dihydrochalcones and acid derivatives were active against F. solani and Phytophthora sp., of which 3 (32.5 ± 3.3 µM) and 4 (26.7 ± 5.3 µM) were the most active compounds, respectively. The preliminary structure–activity relationship allowed us to establish that prenylated chains and the carboxyl group are important in the antifungal activity of benzoic acid derivatives. Likewise, a positive influence of the carbonyl group on the antifungal activity for dihydrochalcones was deduced.

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Biodirected Synthesis of Silver Nanoparticles Using Aqueous Honey Solutions and Evaluation of Their Antifungal Activity against Pathogenic Candida Spp.

International Journal of Molecular Sciences ◽

10.3390/ijms22147715 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7715

Author(s):

Grzegorz Czernel ◽

Dominika Bloch ◽

Arkadiusz Matwijczuk ◽

Jolanta Cieśla ◽

Monika Kędzierska-Matysek ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antifungal Activity ◽

Fungal Pathogens ◽

Fungal Growth ◽

Disc Diffusion ◽

Candida Spp ◽

Antifungal Effect ◽

Synthesis Of Nanoparticles ◽

Honey Solution ◽

Diffusion Assay

Silver nanoparticles (AgNPs) were synthesized using aqueous honey solutions with a concentration of 2%, 10%, and 20%—AgNPs-H2, AgNPs-H10, and AgNPs-H20. The reaction was conducted at 35 °C and 70 °C. Additionally, nanoparticles obtained with the citrate method (AgNPs-C), while amphotericin B (AmB) and fluconazole were used as controls. The presence and physicochemical properties of AgNPs was affirmed by analyzing the sample with ultraviolet–visible (UV–Vis) and fluorescence spectroscopy, scanning electron microscopy (SEM), and dynamic light scattering (DLS). The 20% honey solution caused an inhibition of the synthesis of nanoparticles at 35 °C. The antifungal activity of the AgNPs was evaluated using opportunistic human fungal pathogens Candida albicans and Candida parapsilosis. The antifungal effect was determined by the minimum inhibitory concentration (MIC) and disc diffusion assay. The highest activity in the MIC tests was observed in the AgNPs-H2 variant. AgNPs-H10 and AgNPs-H20 showed no activity or even stimulated fungal growth. The results of the Kirby–Bauer disc diffusion susceptibility test for C. parapsilosis strains indicated stronger antifungal activity of AgNPs-H than fluconazole. The study demonstrated that the antifungal activity of AgNPs is closely related to the concentration of honey used for the synthesis thereof.

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Protective Antifungal Activity of Plantago major Extract Against the Phytopathogenic Fungi Phytophthora cinnamomi, Diplodia corticola and Colletotrichum Species

Proceedings ◽

10.3390/foods_2020-07678 ◽

2020 ◽

Vol 70 (1) ◽

pp. 94

Author(s):

Cláudia Ferreira ◽

Rui Oliveira

Keyword(s):

Antifungal Activity ◽

Secondary Metabolites ◽

Plant Extracts ◽

Phytophthora Cinnamomi ◽

Fungal Infections ◽

Petri Dish ◽

Phytopathogenic Fungi ◽

Colletotrichum Acutatum ◽

Lower Probability ◽

Plantago Major

Synthetic fungicides for crops protection raise environmental and human concerns due to accumulation in edible vegetables, showing significant toxicity to humans, and in soil, groundwater and rivers, affecting ecological balance. In addition, they are prone to the development of resistant strains because of the single target-based mechanism of action. Plant extracts provide attractive alternatives, as they constitute a rich source of biodegradable secondary metabolites, such as phenols, flavonoids and saponins, which have multiple modes of antifungal action and a lower probability of the development of resistant fungi. This work has the objective of identifying plant extracts with antifungal activity, aiming to contribute to food safety and sustainable agricultural practices. We selected a saponin-containing plant, Plantago major, and extracted secondary metabolites with 50% (v/v) ethanol, dried by evaporation, and dissolved in water. For antifungal activity, the phytopathogenic fungi Colletotrichum acutatum, Colletotrichum gloeosporioides, Colletotrichum godetiae, Colletotrichum nymphaeae, Diplodia corticola and Phytophthora cinnamomi were selected because they affect fruits and vegetables, such as strawberry, almond, apple, avocado, blueberry and chestnut trees. The aqueous extract was incorporated into PDA medium at different concentrations and mycelial discs were placed in the center of each Petri dish. Growth was measured as the radial mycelial growth at 3, 6, and 9 days incubation at 25 °C in the dark. The maximum growth inhibition (32.2%) was obtained against P. cinnamomi with 2000 µg/mL extract followed by C. gloeosporioides (25.7%) on the sixth day and by C. godetiae and C. nymphaeae (21.1%) on the ninth day. Results show that P. major presents antifungal activity in all phytopathogenic fungi tested and the extract can be used to protect important crops, by inhibiting the development of fungal infections and promoting food security and a sustainable agriculture.

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Activity of Alkanediol Alkanoates against Pathogenic Plant Fungi Rhizoctonia solani and Sclerotium rolfsii

Natural Product Communications ◽

10.1177/1934578x1200700930 ◽

2012 ◽

Vol 7 (9) ◽

pp. 1934578X1200700 ◽

Cited By ~ 2

Author(s):

Paraj Shukla ◽

Suresh Walia ◽

Vivek Ahluwalia ◽

Balraj S. Parmar ◽

Muraleedharan G. Nair

Keyword(s):

Antifungal Activity ◽

Ethylene Glycol ◽

Rhizoctonia Solani ◽

Diethylene Glycol ◽

Sclerotium Rolfsii ◽

Phytopathogenic Fungi ◽

Dependent Manner ◽

Acyl Chlorides ◽

Mass Spectral ◽

Dose Dependent

Thirty known dialkanoates of ethylene, propylene and diethylene glycols were synthesized by reacting the glycols with acyl chlorides and their structures confirmed by IR, NMR and mass spectral analyses. They exhibited significant antifungal activity against two phytopathogenic fungi Rhizoctonia solani Kuehn and Sclerotium rolfsii Sacc in a dose dependent manner. Propylene glycol dipentanoate was the most active against R. solani. followed by diethylene glycol dibutanoate and ethylene glycol dibutanoate. Against S. rolfsii ethylene glycol diheptanoate was found to be most active followed by diethylene glycol diisobutanoate As compared to the standard reference benomyl (EC50 5.16 μg/mL), the potential alkanediol dialkanoates showed EC50 in the range of 33 – 60 μg/mL.

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