Evaluation of Native Wine Yeast as Biocontrol Agents Against Fungal Pathogens Related to Postharvest Diseases

Abstract

Changes in consumer expectations have led to increasing demand for novel plant protection strategies, in order to reduce the application of chemical products, reduce the occurrence of new pests and the impact that all these actions generate in the environment. In recent years there have been numerous investigations related to biological control and the use of microorganisms as new control strategies. As part of integrated disease management, antagonistic microorganisms have been investigated lately and presented great interest. Such microorganisms can be applied in conventional and in organic farming as biological control agents (BCA). Many of these microorganisms are present in the microbial ecology generating interactive associations between surrounding microorganisms. For these reasons, it has become necessary to search new natural antimicrobial agents as alternatives to synthetic and chemical products. It has been discovered that there are microorganisms, particularly yeasts, that have antagonistic activity and different mechanisms of action, indicating that they could be interesting candidates for the development of BCA. Here, we evaluate the antagonist effect of four endophytic yeast, Cryptococcus antarcticus, Aureobasidium pullulans, Cryptococcus terrestris and Cryptococcus oeirensis over the growth of Botrytis cinerea, Monilinia laxa, Penicillium expansum and Geotrichum candidum in in vitro assays (inhibition zone diameter assay and confrontation assay).The results revealed that the four yeast strains evaluated showed antagonistic activity against the phytopathogens tested, suggesting that these yeasts produce compounds capable of inhibiting the growth of fungi and, depending on the assay, the evaluated antagonist-yeasts have differential biocontrolling-effect against the postharvest pathogens tested.

Biocontrol potential of wine yeasts against four grape phytopathogenic fungi disclosed by time-course monitoring of inhibitory activities

“…In addition, while being in their natural ecosystem they can evolve better and easily adjust to the associated environmental conditions, thus being more prone to demonstrate effective and consistent biocontrol activity against grapes phytopathogens ( Parafati et al, 2015 ; Pretscher et al, 2018 ; Pereyra et al, 2021 ). In fact, most of the species represented in our collection include previously reported antagonists of grape phytopathogenic fungi ( Suzzi et al, 1995 ; Bleve et al, 2006 ; Raspor et al, 2010 ; Nally et al, 2012 ; Pantelides et al, 2015 ; Lemos Junior et al, 2016 ; Cordero-Bueso et al, 2017 ; Pretscher et al, 2018 ; Reyes-bravo et al, 2019 ) while the antagonistic potential of Nakazawaea ishiwadae and Yamadazyma mexicana are herein reported for the first time.…”

“…However, the lack of standardized protocols for in vitro dual culture assays is a major drawback for the direct comparison of the results obtained in the different studies and the accomplishment of definitive classification of antagonistic yeasts. Indeed, the level of yeast inhibition has been distinctly evaluated, either by arbitrary scales ( Suzzi et al, 1995 ; Bleve et al, 2006 ), inhibition halos ( Nally et al, 2012 ; Cordero-Bueso et al, 2017 ; Reyes-bravo et al, 2019 ) or percentages ( Raspor et al, 2010 ; Pantelides et al, 2015 ; Lemos Junior et al, 2016 ; Pretscher et al, 2018 ; Reyes-bravo et al, 2019 )( Lemos Junior et al, 2016 ; Reyes-bravo et al, 2019 ) obtained by comparing the mold colony sizes in the presence of the yeasts with that for its single culture at a defined end time point. In addition, the use of a panoply of distinct methodologies related with the yeast inoculation technique (incorporation, spot, streak or spread plating), type of mold inoculum (spore suspension or mycelial plug), nature of interaction (direct or indirect contact), period of incubation and the culture medium used, introduce even more entropy in the data comparison.…”

“…The prospect of using these so-called “wine yeasts” as antagonists of grape fungal pathogens led to a variety of in vitro screenings using dual-culture assays ( Suzzi et al, 1995 ; Bleve et al, 2006 ; Raspor et al, 2010 ; Nally et al, 2012 ; Pantelides et al, 2015 ; Lemos Junior et al, 2016 ; Cordero-Bueso et al, 2017 ; Pretscher et al, 2018 ; Reyes-bravo et al, 2019 ). In addition to the assessment of their inhibitory activity, and according to the experimental setup used, this screening methodology also gave insights on the potential modes of action associated, typically the production of antimicrobial compounds ( Köhl et al, 2019 ).…”

“…californica with a strong antagonistic action against B. cinerea , A. carbonarius and P. expansum . More recently, Reyes-bravo et al (2019) reported strains of Aur. pullulans, Cry.…”

Biochemical and Biotechnological Insights into Fungus-Plant Interactions for Enhanced Sustainable Agricultural and Industrial Processes

“…The endophytic yeasts Naganishia antarctica , Aureobasidium pullulans , Cryptococcus terrestris , and Filobasidium oeirense also proved to be potential biocontrol agents against the pathogenic fungi B. cinerea , Monilinia laxa , Penicillium expansum , and Geotrichum candidum [ 70 ]. In the case of A. pullulans, the antifungal activity involved in the biological control of the pathogens was attributed to the alkaline protease produced by this yeast [ 71 ].…”