Antifungal activity of native yeasts from different microenvironments against Colletotrichum gloeosporioides on ripe olive fruits

Abstract

Anthracnose is a fungal disease caused by Colletotrichum species, which mainly affects olive fruits during ripening. The use of yeasts from related and unrelated microenvironments in the control of plant pathogens has become an alternative to the use of synthetic fungicides. The objectives of the present study were to evaluate in vitro biocontrol strategies against C. gloeosporioides, in order to select native antagonistic yeasts isolated from different microenvironments, and to verify the in vivo biocontrol activity on ripe olive fruits. The potential human pathogenicity of the antagonistic yeasts was also considered. A total of 241 wild yeasts from diverse olive cultures and vitivinicultural microenvironments were assayed in vitro and in vivo for their antagonistic effect against the pathogen C. gloeosporioides. Ninety-two yeasts with in vitro characteristics of competitiveness such as niche overlap, dominance against the pathogen, reduction of fungal growth and production of antifungal metabolites were examined on ripe olive fruits. Nine biocontrol yeasts, three from fermenting grape must and six from olive fruits, leaves and branches in vivo reduced the incidence and severity of C. gloeosporioides. According to the 42°C test, which assays for pseudohyphal formation and phospholipase production, these biocontrol yeasts did not present a health risk to humans. Microenvironments with selective stress factors can be relevant sources of microorganisms with biocontrol purposes.

Effect of Saccharomyces cerevisiae and Spirulina platensis on Suppressing Root-knot Nematode, Meloidogyne incognita Infecting Banana Plants under Greenhouse Conditions

“…Furthermore, the effect of some yeasts on RKN might be due to the potency of these yeasts to change carbohydrates to produce ethyl alcohol and CO 2 that are highly toxic to RKN (Azhar et al, 2017). The other mechanisms of yeast to control activity for pests may introduce competition for some nutrients, parasitism and may induce resistance in plants; and also make physical and chemical soil structures undesirable for pathogenic agents to grow (Zhou et al, 2018;da Cunhaa et al, 2018;Pesce et al, 2018). Consequently, the treatment with the yeast, S. cerevisiae could inhibit of RKNs community and galls formation on cucumber root through its effects on the nematode life cycle to induce plant resistance (Karajeh, 2013).…”

“…Hence, it is remarkable to discover an effective alternative methods to include safety food production and environmentally ecofriendly crop production (Naz et al, 2016). Applicability of some yeasts are used for controlling fungal diseases on fruits (Nally et al, 2012;Pesce et al, 2018), and also using as bio-control agents for post-harvest diseases of many crops (Punja 1997;da Cunha et al, 2018). In a similar study by Karajeh, 2013, high concentration of total phenolics compounds in roots of some yeasts-treated plants and hydrogen peroxide (H 2 O 2 )-treated plants provides a sign on the function of the yeast to induce resistance of the plants against pests.…”

Extension of Avocado Fruit Postharvest Quality Using Non-Chemical Treatments

“…Biocontrol agents are believed to compete for nutrients as their primary mode of action against fungal pathogens. Other mechanisms, involving the use of cell wall-degrading enzymes, production of antifungal diffusible and volatile metabolites, induction of host resistance and mycoparasitism have been cited in the bio-control activity of yeasts [72]. Although several antagonists of postharvest pathogens have been identified and tested in the laboratory, semi-commercial, and commercial settings, the full commercial potential has not been realised [73].…”

Almond Anthracnose: Current Knowledge and Future Perspectives

“…All the studies concerning biologic control against Colletotrichum spp. have been conducted on anthracnose of other host plants such as apple, avocado, chili, mango, olive, papaya or strawberry [60][61][62][63][64][65].…”