The aim of this study was to investigate the effect of cinnamon and ginger oils on some biological, physical and physico-chemical properties of chitosan-carboxymethyl cellulose films emulsified with ...oleic acid. Films containing cinnamon oil showed higher antifungal activity in vitro against Aspergillus niger than those containing ginger. Unlike ginger-based materials, the film crystallinity decreased with an increasing concentration of cinnamon oil. The microstructure of the active films was evaluated by scanning electron microscopy and results showed a distinct morphology depending on the composition of essential oils (EOs). As expected, both EOs decreased water vapor permeability of the active films, with a higher decreasing effect for cinnamon. Resulting water contact angles were improved by 36–59% for ginger films and 65–93% for cinnamon films, depending on the EO concentration. Regarding mechanical properties, highest concentrations of EOs led to an improvement of 328% and 111% of the elongation with cinnamon and ginger, respectively. The different behavior of both EOs regarding physical, mechanical, thermal and water vapor permeability properties could be attributed to differences in their chemical compositions. The presence of cinnamaldehyde, in cinnamon essential oil, can create many kinds of interactions with the network made by carboxymethyl cellulose, chitosan and oleic acid. Findings in this work suggest that EOs and especially cinnamon oil could be used to plasticize chitosan-carboxymethyl cellulose films while improving moisture permeability and maintaining antifungal activity. This bio-based material could be of interest for food preservation.
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•Chitosan and carboxymethyl cellulose were successfully associated to create a film.•Cinnamon oil strongly plasticized chitosan - carboxymethyl cellulose films.•Cinnamon oil showed higher antifungal activity in vitro against Aspergillus niger than ginger oil.•Differences in film properties were likely due to cinnamaldehyde in cinnamon essential oil.
Chitosan edible films and coatings have shown great promise for their application in food preservation and also are promising systems to be used as essential oil (EO) carriers. This review reports ...the most recent and relevant studies concerning chitosan films and coatings containing EOs. The effect of EO incorporation on the antioxidant, antibacterial and antifungal activities of chitosan films and coatings in vitro and in vivo, as well as their applications in food systems have been discussed. In general, incorporation of EOs significantly increased the antioxidant, antibacterial and antifungal efficacy of chitosan films and coatings in vitro. EO-incorporated films and coatings also showed greater effectiveness against postharvest fungi and foodborne bacteria in food systems than pure films and coatings. The application of chitosan films and coatings containing EOs usually led to an extension of the shelf-life and reduction of lipid peroxidation of fish and meat products over pure chitosan films and coatings. In addition, chitosan coatings incorporated with EOs were more effective in maintaining fruit and vegetable quality, and controlling their postharvest decay during storage and shelf life than pure chitosan coatings.
•Incorporation of EOs increased antioxidant and antimicrobial efficacy of chitosan films and coating.•Chitosan-EOs were more effective in extension of shelf-life and maintaining quality than chitosan.•Chitosan-EOs were more effective against pathogen and fungi in food than chitosan.
Biological reduction agents are being explored worldwide to minimize the effects of toxic chemicals used in nanoparticle fabrication. The present study states a green approach for the synthesis of ...zinc oxide nanoparticles employing aqueous flower extract of Nyctanthes arbor-tristis. Flower extract was used as the biological reduction agent for synthesizing zinc oxide nanoparticles from zinc acetate dihydrate. Synthesis conditions were optimized for maximal and narrow size range synthesis of zinc oxide nanoparticles. The resultant nanopowder was characterized using various analytical techniques, such as UV–Visible spectroscopy, Fourier Transform Infrared spectroscopy, X-ray diffraction, Dynamic Light Scattering and Transmission Electron Microscopy. The nanopowder was stored in dried form and was found to be stable after 4months. The size range of nanoparticles obtained upon synthesis at optimum conditions was 12–32nm as reported by TEM. X-ray diffraction studies confirmed the crystalline nature of the nanoparticles indicating particle size within the range provided by electron microscopy data. Nanoparticles were tested for their antifungal potential and were found to be active against all five tested phytopathogens with lowest MIC value recorded as 16μg/mL. Hence, an easy and effective green approach for synthesis of zinc oxide nanoparticles, with efficient antifungal potential is reported in this study.
Objective: In order to prevent and control the infection of Candida albicans, the antifungal activity, possible mechanism of myriocin against C. albicans and its biofilm were studied. Methods: The ...antifungal activity of myriocin was investigated by microdilution method. The effect of myriocin on fungal cell wall or membrane was evaluated by adding sorbitol, ergosterol or phytosphingosine (PHS). The damage to the cell membrane was investigated with propidium iodide (PI) staining and visualized by Scanning electron microscope (SEM). The effects on biofilms and extracellular polysaccharides (EPS) were observed by crystal violet staining method and phenol-sulfuric acid method respectively. The adhesion of C. albicans cells to hydrocarbons was tested to evaluate cell surface hydrophobic (CSH). The combined effects of myriocin and antifungal drugs commonly used in clinical practice were investigated by using the checkerboard microdilution method. Results: MICs were found to be 0.125~4 µg/ml. Myriocin was found to affect both cell wall and cell membrane. After exposure to myriocin, biofilm and EPS were found to be inhibited and removed, and the CSH was decreased. The combined fungistasis of myriocin and voriconazole (VCZ) or amphotericin B (AMB) were additive. Conclusion: Myriocin had significant antifungal activity against C. albicans, and the antifungal mechanisms might be cell wall and membrane damage. Myriocin effectively inhibited and eliminated biofilms, and its mechanism may be related to the inhibition of EPS and CSH.
Endophytes colonize the interior of plant tissues without causing any damage to their hosts. The plant Sapindus saponaria L., popularly known as ‘sabão-de-soldado’, presents a diversified endophytic ...microbiota and also medicinal properties. Endophytic microorganisms may produce secondary metabolites with different biotechnological properties. The present study aimed to evaluate the in vitro antibacterial and antifungal capacity of the crude extract of secondary metabolites produced by the endophytic bacteria P. aeruginosa SS93 isolated from S. saponaria leaves. The metabolites extract was obtained using the organic solvent ethyl acetate, and the antimicrobial activities were tested against six pathogenic bacteria (Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853, Shigella flexneri ATCC 12022, Salmonella enterica CCCD a016, Escherichia coli ATCC 25922, and Staphylococcus aureus ATCC 25923), and pathogenic fungi (Fusarium oxysporum, Glomerella sp., Sphaceloma sp., Fusarium solani, Maniliophtora perniciosa, and Sclerotinia sclerotiorum), by agar diffusion method. In the antibacterial assay, the best results were obtained against E. faecalis and S. aureus, where the formation of inhibition halos was observed in all tested concentrations, especially at 500 and 700 µg mL-1. Positive inhibitory activity against phytopathogenic fungi was observed, with the highest inhibition recorded against F. oxysporum (61.1%), followed by Sphaceloma sp. (55.7%), M. perniciosa (35.6%), F. solani (34.4%), and Glomerella sp. (30.4%).
Gray mold disease, caused by Botrytis cinerea is a major postharvest disease impacting fruits such as strawberries and tomatoes. This study explores the use of volatile organic compounds (VOCs) ...produced by Bacillus spp. as eco-friendly biocontrol agents against B. cinerea. In vitro experiments demonstrated that VOCs from Bacillus sp. LNXM12, B. thuringiensis GBAC46, and B. zhanghouensis LLTC93-VOCs inhibited fungal growth by 61.2%, 40.5%, and 21.6%, respectively, compared to the control. LNXM12 was selected for further experiments due to its highest control efficacy of 58.3% and 76.6% on tomato and strawberry fruits, respectively. The LNXM12 VOCs were identified through gas chromatography–mass spectrometry (GC–MS) analysis, and 22 VOCs were identified. Synthetic VOCs with the highest probability percentage, namely ethyloctynol, 3-methyl-2-pentanone (3M2P), 1,3-butadiene-N, N-dimethylformamide (DMF), and squalene were used in experiments. The results showed that the synthetic VOCs ethyloctynol and 3M2P were highly effective, with an inhibition rate of 56.8 and 57.1% against fungal mycelium radial growth at 120 μg/mL on agar plates. Trypan blue staining revealed strongly disrupted, deeper blue, and lysed mycelium in VOC-treated B. cinerea. The scanning and transmission electron microscope (SEM and TEM) results showed that fungal mycelium was smaller, irregular, and shrunken after synthetic VOC treatments. Furthermore, the synthetic VOCs Ethyloctynol and 3M2P revealed high control efficacy on tomatoes and strawberries infected by B. cinerea. The control efficacy on leaves was 67.2%, 66.1% and 64.5%, 78.4% respectively. Similarly, the control efficiency on fruits was 45.5%, 67.3% and 46.3% 65.1%. The expression of virulence genes in B. cinerea was analyzed, and the results revealed that selected genes BcSpl1, BcXyn11A, BcPG2, BcNoxB, BcNoxR, and BcPG1 were downregulated after VOCs treatment. The overall result revealed novel mechanisms by which Bacillus sp. volatiles control postharvest gray mold disease.
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•The volatile organic compounds of Bacillus sp. LNXM12 possesses antifungal activity.•The synthetic VOCs showed strong biocontrol efficacy against B. cinerea.•VOCs suppressed B. cinerea metabolic activity, leading to ultrastructural changes in the fungal mycelium.•LNXM12-VOCs downregulated the expression of virulence-related genes.•LNXM12-VOCs controlled the gray mold disease on tomatoes and strawberries.
This study aims to examine the effectiveness of mycocins produced by Wickerhamomyces anomalus in inhibiting Malassezia pachydermatis, a yeast commonly found in the ear canal of dogs. M. pachydermatis ...has a zoophilic origin and can be found in mammals, and frequently in dogs, where it mainly colonizes the ear canal region and the skin, leading to lesions that are difficult to treat. The antimicrobial mechanism was evaluated using dilutions of supernatant with enzymatic activity, which may include β-glucanases, glycoproteins known to act on microorganism cell walls. However, it is important to note that this supernatant may contain other compounds as well. β-glucanases in the mycocins supernatant were found at a concentration of 0.8 U/mg. The susceptibility of M. pachydermatis isolates was tested using the microdilution method. The isolates suffered 100% inhibition when tested with the culture supernatant containing mycocins. In the proteinases production test, 44% of the isolates tested were strong proteinases producers. Subsequently all these isolates suffered inhibition of their activity when tested in research medium containing mycocins supernatant at a subinhibitory concentration of β-glucanases. This shows that mycocins can inhibit the production of proteinases, a virulence factor of M. pachydermatis. The viability test showed the antifungal action of mycocins in inhibiting the viability of M. pachydermatis cells after a period of 8 hours of contact. These results support the antimicrobial potential of mycocins and their promise as a therapeutic option.
•Mycocins with β-glucanase activity from Wickerhamomycer anomalus can inhibit Malassezia pachydermatis.•Mycocins from Wickerhamomycer anomalus effectively inhibit proteinases produced by Malassezia pachydermatis.•Malassezia pachydermatis cells became non-viable after contact with mycocins supernatant, which showed β-glucanase activity.
The antifungal activity of Serratia plymuthica CCGG2742, a bacterial strain isolated from grapes berries skin, against a phytopathogenic fungus isolated from blueberries was evaluated in vitro and in ...vivo. In order to characterize the wild fungal isolate, phylogenetic analysis using concatenated DNA sequences from the RPB2 and TEF1 genes and of the ITS region was performed, allowing the identification of the fungal isolate that was called Alternaria tenuissima CC17. Hyphae morphology, mycelium ultrastructure, conidia and reproductive structures were in agreement with the phylogenetic analysis. The antifungal activity of the S. plymuthica strain was dependent on the composition of the culture medium. The greatest inhibition of mycelial growth of A. tenuissima CC17 by S. plymuthica CCGG2742 was observed on YTS medium, which lacks of an easily assimilable carbon source. Fungal growth medium supplemented with 50 % of bacterial supernatant decreased the conidia germination of A. tenuissima CC17 up to 32 %. Preventive applications of S. plymuthica CCGG2742 to blueberries and tomato leaves at conidia:bacteria ratio of 1:100, protected in 77.8 ± 4.6 % and 98.2 ± 0.6 % to blueberries and tomato leaves from infection caused by A. tenuissima CC17, respectively. To the best of our knowledge, this is the first report on the antifungal activity of S. plymuthica against A. tenuissima, which could be used as a biological control agent of plant diseases caused by this fungal species. In addition, the results of this work could be a starting point to attribute the real importance of A. tenuissima as a pathogen of blueberries in Chile, which until now had been considered almost exclusively to A. alternata. Likewise, this research could be relevant to start developing highly effective strategies based on S. plymuthica CCGG2742 for the control of this important phytopathogenic fungus.
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•Serratia plymuthica CCGG2742 presents antifungal activity against Alternaria tenuissima.•The antifungal activity was dependent on the composition of the culture medium.•Bacterial supernatant decreased the mycelial development and conidia germination of A. tenuissima.•S. plymuthica CCGG2742 protected to blueberries and tomato leaves from infection caused by A. tenuissima.
The antifungal activity of the ethanolic hot extract of the green filamentous species Chlorophyta was evaluated in vitro at various doses (25, 50, and 100 mg/ml) and shown to be effective. Antifungal ...activity was performed by evaluating the percentage inhibition growth method against some fungus were obtained from the postgraduate laboratories in the Department of Biology - Faculty of Science / University of Mustansiriya (Aspergillus niger, Fusarium oxysporum, Penicillium sp. and Rhizoctonia solani ). As a result of the research, it was discovered that the hot ethanol extract of Ulothrix sp had the most significant effect (91.8 %) on Rhizoctonia solani growth inhibition at a concentration of 100 mg/ml and the minor effect (22.4 %) at a concentration of 25 mg/ml against Aspergillus niger growth inhibition. It was discovered by primary chemical analysis of active substances that alkaloids, Terpenes, Saponines, phenols, Flavones, Resins, Steroids, and tannins were present in hot ethanolic alga extract. Finally, the GC-mass analysis performed on Ulothrix sp extracts revealed a large number of antibacterial activity-producing substances. Because the current research shows that algae have antifungal activity, it has the potential to be developed as a new source of active chemicals for human and plant consumption in a variety of applications shortly.
Keywords: Antifungal activity, Ulothrix, Active compounds,
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