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It is difficult to effectively eradicate C. albicans using traditional antifungal agents, mainly because the low permeability of the C. albicans cell wall creates strong drug ...resistance. The aim of this study was to investigate the synergistic fungicidal effect and the underlying mechanisms of low-frequency and low-intensity ultrasound combined with a treatment of amphotericin B-loaded nanoparticles (AmB-NPs) against C. albicans. AmB-NPs were prepared by a poly(lactic-co-glycolic acid) (PLGA) double emulsion method. C. albicans was treated by AmB-NPs combined with 42 kHz ultrasound irradiation at an intensity of 0.30 W/cm2 for 15 min. The results demonstrate that the application of ultrasound enhanced the antibacterial effectiveness of AmB-NPs (P < 0.01), and the antifungal efficiency increased significantly with increasing AmB concentration of drug-loaded nanoparticles under ultrasonic irradiation. Additionally, the mycelial morphology of C. albicans suffered from the most severe damage and loss of normal microbial morphology after the combined treatment of AmB-NPs and ultrasound, as revealed by electron microscope. Furthermore, we verified the safe use of low-frequency ultrasound on exposed skin and discussed the potential mechanism of ultrasound enhanced fungicidal activity. The results reveal that the mechanism may be associated with the ultrasound cavitation effect and an increase in intracellular reactive oxygen species.
Aspergillus parasiticus (A. parasiticus)
is known for producing aflatoxins and is a major threat to the food industry. Green synthesis of nanoparticles (NPs) is a cost-effective and ...environment-friendly approach. A variety of NPs have been explored as antifungal agents; however, their antifungal characteristics need to be further enhanced to compete with traditional fungicides. The present work describes the green synthesis of ZnO and CuO NPs by precipitation method using aqueous leaf extract of
Manilkara zapota
and their surface modification through polyaniline (PANI). Still, there is no published study on the application of PANI-coated particles as antifungal agents against
A. parasiticus and hence
was the focus of this work. The polymer-coated NPs were synthesized, characterized, and investigated for their antifungal properties against
A. parasiticus
. Textural and structural characterization of PANI-coated and non-coated ZnO and CuO NPs were confirmed through FT-IR, SEM, and XRD techniques. The PANI-coated NPs presented higher fungal growth inhibition (%) as compared to the non-coated ones. The maximum inhibition of 77 ± 2% (
n
= 3) was shown by PANI/ZnO NPs at a concentration of 12 mmol L
−1
and 72 h of incubation. The non-coated NPs presented a lower inhibition rate with respect to their coated NPs, thus justifying the role of polymeric coating in improving antifungal efficiency.
This study aimed to isolate and identify phosphate solubilizing microorganisms from rhizosphere soils and evaluate their plant growth-promoting traits in vitro. Fifty-six potential ...phosphate-solubilizing bacteria were isolated, and ten isolates were selected for further characterization based on their performance. Burkholderia species were found to be the predominant solubilizers of insoluble phosphorus sources. Two strains, B. vietnamiensis-OP984178 and B. ambifariaOP984173, showed the ability to release soluble phosphorus from different sources, including tricalcium phosphate, ferric phosphate, and hard Minjingu rock phosphate powder. Both isolates also demonstrated production of indole acetic acid, with B. vietnamiensis-OP984178 and B. ambifaria-OP984173 producing up to 23.45 microg/ml and 24.24 microg/ml, respectively. Furthermore, the strains showed antifungal efficiencies of 31.48% and 24.81%, respectively, when co-inoculated with Fusarium proliferatum-MZ497514 on potato dextrose agar. The study also identified the nitrogen fixation potential of the two strains. Overall, the findings highlight the potential of the selected Burkholderia strains as biofertilizers and biocontrol agents, making them valuable candidates for sustainable agriculture practices. Further research is recommended to explore the potential of these strains using test crops.
In the wake of an increased attention on the eco-friendly biopesticidal products and the rising market requirements for organic agents, lipopeptides compounds have been described as biological ...control agents which improve the overall health growth and development of plants. Nevertheless, their high production cost constitue the major flaw in their wide use to control plant diseases. The present article aims to formulate an economic media for lipopeptides production by
Bacillus mojavensis
A21 for application as natural fungicides for plant disease treatment. We herein demonstrated the suitability of the potato waste, as low cost substrate, for lipopeptides production. Moreover, sea water was found to be a good mineral salts sources. In the second part of this study, we investigate the inhibitory activity of A21 lipopeptides against the phtopathogenic
Fusarium
sp. The in vitro test showed a minimal inhibitory concentration of about 0.3 mg/ml. The microscopic examination, of the treated
Fusarium
revealed an excessive lysis of the mycelia ultrastructure with destructed spores. The in vivo antagonist activity was confirmed towards the infected potato tubers. A21 lipopeptides are effective in decreasing by about 78.26% and 60.68% when applied as preventive and curative treatments, respectively, as compared to the untreated tubers.
•Coupled effect contribute to the consist antifungal effect after 4–7 months.•The most suitable protocol of the protection materials application is established.•The metastable state of surfaces has ...an important impact on antifungal efficiency.•The nature of protection materials has the great influence on antifungal properties.
The goal of the paper is the investigation of synergistic action of newly developed consolidants and LDH_TiO2 photocatalytic suspension on the characteristics (antifungal efficiency and surface properties) of the selected mineral substrates: brick and render. There were two different application protocols employed: protocol (1) the fresh photocatalytic suspension was applied on already consolidated substrates aged for 1, 2, 4 and 7 months, and protocol (2) only once on all specimens aged 1 month after the consolidant application. This study provides an insight into the synergistic effect of the applied materials on the antifungal activity, hydrophilicity and performances of the substrates’ surface during UV irradiation. The decrease of OH− ions on the surface, revealed from the photocatalytic suspension, showed a positive effect on the surface stability and antifungal properties of the mineral surface. Based on the obtained results, the most suitable protocol for the application of the photocatalytic suspension on the already consolidated and aged porous substrates has been adopted.
The work studies the photocatalytic activity and the antifungal efficiency of the TiO₂/Zn-Al coatings placed on the target commercial façade paints. The photocatalytic active nanocomposite based on ...TiO₂ and Zn-Al-layered double hydroxides (ZnAl-LDHs) was synthesized by a wet impregnation technique with 3 % w/w TiO₂. The freshly prepared suspension was applied by spray technique on the surfaces of the white façade paints. The goal of the work was to develop a method that quickly quantifies the antifungal activity of the commercial façade paints with and without biocidal components covered with a photocatalytic coating. The essence of the proposed method is the monitoring of the fungal growth (artificial ageing conditions) and the quantification of its development (UV-A 0.13 mWcm⁻²) on the façade paint surfaces. A special fungus nutrient (potato dextrose agar (PDA)) was inoculated with the spores of the Aspergillus niger ATCC 6275, and the test samples (façade paints with and without photocatalytic coating) were placed on the inoculated nutrient in the petri dishes. The images of the fungal growth on the samples of the facade paints, during a period of 5 days, were imported into Matlab R2012a where they were converted to binary images (BW), based on the adequate threshold. The percentage of the surface coverage was calculated by applying the specifically written program code which determines the ratio of the black and white pixels. The black pixels correspond to the surface covered with hyphae and mycelia of the fungus.
ANTIFUNGAL EFFICIENCY OF SLAG BASED CEMENT COMPOSITES Smoláková, Michaela; Eštoková, Adriana; Václavík, Vojtěch
International Multidisciplinary Scientific GeoConference : SGEM,
01/2018, Letnik:
18, Številka:
6.3
Conference Proceeding
Blast furnace slag (BFS) is used for preparation of common cements, sulfate-resisting and chemical-resisting cements and cement mortars. Using BFS as a concrete or mortar addition results in several ...advantageous properties such as high resistance to acid attack (sulphuric, nitric acids), low chloride permeability, high durability and low capillary porosity. Because of these properties using BFS in cement composites can decrease the effect of biodegradation induced by various microorganisms. Bio-corrosion is caused by biogenic organic and mineral acids, which result from metabolic activity of microorganisms like fungi, bacteria or yeasts. In this article, the potential antifungal properties of BFS were analysed regarding the selected species of fungi (Cladosporium spp., Aspergillus niger and Penicillium glabrum). Antifungal efficiency was studied on cement composites with different share (65%, 75%, 85% and 95%) of BFS. Moderate antifungal effectivity of composites with slag was confirmed for two from three strains of studied fungi Cladosporium spp. and Aspergillus niger.
The Ag and Ag–SiO
2 nanoparticles were synthesized by γ-irradiation, and characterized by field-emission transmittance electron microscopy (FE-TEM), field-emission scanning electron microscopy ...(FE-SEM), and energy dispersive X-ray spectroscopy (EDXS). The electron microscopy images show that well-dispersed Ag nanoparticles of about 7
nm were attached to the surface of SiO
2 nanoparticles of about 350
nm. Antibacterial efficiency of the Ag–SiO
2 nanoparticles was tested against
Salmonella enterica serovar Typhimurium by measuring the optical density (OD). Without Ag–SiO
2 particles, the
S. enterica serovar Typhimurium grow gradually, and reach a steady state (fully grow) in about 6
h. At the presence of Ag–SiO
2 particles at 50
ppm, their growth became much slower, reaching a steady state after about 24
h. With Ag–SiO
2 particles at 100
ppm, they did not grow fully even after 58
h. The antifungal efficiency of the Ag–SiO
2 nanoparticles against
Botrytis cinerea was about 65.0, 99.9, and 99.9% at the concentrations of the particles of 10, 50, and 100
ppm, respectively.
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