Yeast Saccharomyces cerevisiae is a unique model for studying the molecular mechanisms of exotoxin-mediated antagonistic relationships between coexisting microorganisms. The synthesis of yeast toxins can be considered as an example of allelopathy and environmental competition. The elucidation of the role of allelopathy in the formation of microbial communities is of great interest for modern ecology. Yeast toxins are widely used in medicine, the food industry and biotechnology. The review examines the nature of exotoxins, the mechanisms of inheritance and interaction of the virus and yeast cells, as well as the prospects for their practical application.