Investigating the characteristics of killer yeasts and their applications in food: a review
Subject Areas :Azita Faraki 1 , MohammadReza Rezaeifard 2
1 - Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
2 - Department of Food Industry and Technology, Faculty of Veterinary Medicine, University of Semnan, Semnan, Iran
Keywords: Killer yeasts, Biocontrol agents, saccharomyces cerevisiae, protein or glycoprotein toxins, bacteriocin activity,
Abstract :
Yeasts have been discovered and used for many years. They are so valuable and practical. In addition to their benefits in food production, their use as a biocontrol and protective agent is considered a great advantage. Among the yeasts in the environment, there is a group called killer yeasts, which, according to research, play an important role in controlling other microorganisms (other yeasts or bacteria). Killer yeasts can be classified in different aspects, but in general, the most important known killer yeast is saccharomyces cerevisiae. The toxins secreted by these yeasts have the role of inhibiting the target organisms in the environment. The nature of these toxins is protein or glycoprotein. Each toxin has its mechanism, and sometimes they are very complicated; there are two important strategies for killer yeasts: (1) competition for food in the environment and (2) penetrating the target cell membrane and destroying it. The most important applications of killer yeasts are fermentation, fundamental biological research, biomedical research, food and feed ingredients, and biocontrol agent. Many studies have been conducted on killer yeasts in various fields, such as the destruction and inhibition of microorganisms in winemaking, bacteriocin activity against pathogens, and antimicrobial activity in food spoilage, fruits, and vegetables. In vivo studies have also been conducted. All these cases indicate the killing activity of killer yeasts and their use as a suitable alternative. It should be mentioned that the dose of killer yeast is so essential. Also, their excessive presence causes problems and safety issues must be considered. Finally, it should be noted that the applications of killer yeasts in the food industry and other fields are increasing and only future studies will demonstrate their real potential of them.