Isolation, identification, and determination of some probiotic activities of yeast from olives and olive products made by traditional methods

Today, the use of probiotics is increasing visibly. Many reasons such as preventing the proliferation of pathogenic microorganisms in the intestine, creating a healthier flora environment, strengthening the intestinal barrier, inhibiting inflammation will continue to keep the interest in probiotics on the agenda. The probiotic properties of yeast are currently being investigated by many studies. Since bacteria can be sensitive to antibiotics, produce toxins and show pathogenicity, preference has been given to yeasts in the selection of probiotics. Due to their numerous and diverse biological activities, yeasts have become promising candidates both in the food industry and in the health sector. It acts as a biological control agent on mold and pathogenic microorganisms to increase flavor in fermented foods, contribute to the development of new functional foods, and in addition to these, increase the shelf life of products. Considering the beneficial effects of yeasts with probiotic properties in terms of health, the need for new probiotic yeast sources comes to the fore, and today, studies to determine the probiotic properties of yeast isolated from foods produced by traditional methods have increased. In this study, 106 yeast isolates were obtained from 56 different sources consisting of olives and olive products obtained by traditional methods. In order to determine the probiotic properties; the aggregation ability of yeasts, ability to survive in gastrointestinal conditions, resistance to bile salt, ability to survive in the presence of antibiotics, resistance to pathogenic microorganisms, their hemolytic activity and ability to adhere to hydrocarbons were analyzed. In order to determine its technological features; Esterase, amylase, catalase and protease enzyme activities of yeast isolates were analyzed. The identification of 25 yeast isolates with the best probiotic properties was first performed with MALDI-TOF MS, and then sequence analysis was continued for the identification of 3 yeast isolates. 4 of the isolates were identified as Wickerhamomyces anomalus and 21 as Yarrowia lypolitica. All yeast isolates have been shown to be different strains of their species. Identified yeasts were taken into stock for use in further studies.