Review: Elucidating the Efficacy of Antagonistic Yeasts by Using Multiple Mechanisms in Controlling Fungal Phytopathogens

The widespread and indiscriminate application of synthetic fungicides against phytopathogens has led to ecological damage and health risks, highlighting the urgent need for eco-friendly alternatives. Antagonistic yeasts provide an environmentally sound alternative to chemical fungicides for crop productivity and environmental conservation, exhibiting direct and indirect control mechanisms against phytopathogens. These microorganisms possess simple nutritional requirements, compatibility with low doses of fungicides and promote public health safety by releasing non-hazardous secondary metabolites. Also, the commercialisation of yeast-based products shows significant potential for protection to a range of commodities, both pre- and postharvest. However, there was only a little literature on the complex control mechanisms working together by various yeast genera against phytopathogens, which were particularly stressed in the review. In addition, the different challenges of biocontrol yeast application and the standard commercialisation protocol were discussed. Future research should focus on optimising formulations and understanding environmental interactions to support biocontrol yeasts' commercialisation and widespread application for crop management.