Yazar "Di Francesco, Alessandra" seçeneğine göre listele

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    Efficacy of volatile organic compounds by Aureobasidium pullulans immobilized on hydrogel spheres against strawberry fungal pathogens
    (Wiley, 2024) Tulukoglu-Kunt, Keziban Sinem; Moret, Erica; Khomutovska, Nataliia; Stenberg, Johan; Di Francesco, Alessandra
    BACKGROUND: The present study explores the use of two different growth supports for the biocontrol yeasts Aureobasidium pullulans M13, C10, R34 and P17, by use of nutrient yeast glucose (NYDA) agar and hydrogel spheres as the support matrix, then evaluates their impact on the production of volatile compounds (VOCs) and the subsequent in vitro and in vivo antagonistic activity against Botrytis cinerea and Colletotrichum acutatum. RESULTS: For the in vitro assay, VOCs secreted by the isolates C10 and M13 encased in the hydrogel spheres showed greater inhibitory activity on the mycelial growth of B. cinerea (70.30%) and C. acutatum (52.35%), respectively, with respect to NYDA. For solid-phase microextraction-gas chromatography-mass spectrometry, VOCs produced by the selected yeasts immobilized in the hydrogel spheres or cultured in the agar were identified. VOCs were grouped as alcohols, ketones, alkane and aldehyde, with phenylethyl alcohol and 1-propanol-2-methyl being the most prominently produced. The analysis revealed variations in both quantity and composition of VOCs among the growth supports, indicating the hydrogel spheres as enhancer distinct metabolic pathways and substrate utilization of the isolates, particularly in the M13 isolate. CONCLUSION: The antifungal activity of the VOCs produced in the hydrogel spheres by the isolates C10 and M13 was assessed on strawberries, demonstrating a significant reduction in disease incidences. (c) 2024 Society of Chemical Industry.
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    Exploring Wild and Local Fruits as Sources of Promising Biocontrol Agents against Alternaria spp. in Apples
    (Mdpi, 2023) Tulukoglu-Kunt, Keziban Sinem; Ozden, Mustafa; Di Francesco, Alessandra
    Biological control agents (BCAs) are a promising option for managing postharvest diseases. Their environmentally friendly nature makes them valuable for sustainable and eco-friendly postharvest disease management. This study evaluated the antagonistic potential of epiphytic yeasts isolated from a local apple genotype known as Nigde Elmasi and a range of wild fruits: rosehip, hawthorn, and wild pear. There were 375 yeast isolates obtained and screened in vitro and in vivo. Initially selected were 32 isolates able to inhibit the growth of Alternaria alternata mycelia in the in vitro experiments and identified using molecular methods as candidate BCAs. These isolates were identified as Aureobasidium pullulans using sequence analysis of the internal transcribed spacer (ITS) and the translation elongation factor EF-1 alpha gene (EF1 alpha). Based on two rounds of in vivo screening, four isolates were subsequently selected for their capability to control the infection of apple fruits under high inoculum pressure. Finally, their volatile and non-volatile antimicrobial activity was tested against Alternaria spp. These findings showed how wild fruits and a local apple genotype could represent a promising source for new BCA isolation. However, further studies are needed to reveal the mechanisms of action of these putative BCAs for application during the postharvest processing and storage of apples.