Probiotics including their combinations with prebiotics known as synbiotics have been extensively studied as an alternatives to antibiotic growth promoters commonly used in livestock breeding. Among many microorganisms that may be useful for their host, the Saccharomyces cerevisiae yeast exhibits probiotic potential. The objective of the research study was to select a S. cerevisiae strain suitable for use as a probiotic in newly developed synbiotic preparations for monogastric animals (poultry, swine). The survivability of yeast strains in the presence of bile salts and under low-pH conditions varied and after 4 h of incubation it ranged from 66 to 94 % and from 68 to 97 %, respectively. The S. cerevisiae ŁOCK 0119 strain was characterised by the highest survival rate; the number of live cells of this strain was reduced not more than 9 % after 4 h of incubation under the fixed conditions. Also, this strain exhibited hydrophilic properties and a strong auto- and co-aggregation potential. The selected yeast strain aggregated with pathogenic bacteria (Salmonella spp., Listeria monocytogenes) to a varying degree ranging between 40 and 75 %. The S. cerevisiae ŁOCK 0119 strain inhibited the adhesion of pathogens to the Caco-2 cells, whereby the adhesion of morbific bacteria attachment was reduced to a varying degree (15 ÷ 37 %). Based on the results obtained, it was concluded that the selected S. cerevisiae yeast strain had beneficial properties since it was able to survive during gastrointestinal passage, to colonize the intestines and to reduce the growth of pathogenic microbiota.
probiotics, S. cerevisiae yeast, hydrophobicity, aggregation, adherence