Some probiotic properties of yeast isolates from infant faeces and Feta cheese

Yeast isolates from infant faeces and Feta cheese were characterized to species level by phenotypic criteria, Randomly Amplified Polymorphic DNA (RAPD)-PCR and mitochondrial DNA (mt-DNA) restriction analysis. Results suggested that there is a good agreement between phenotypic characterization of yeasts and RAPD-PCR at species level; in addition, RAPD-PCR as well as mt-DNA restriction analysis provided good discrimination at strain level. Some technological and probiotic properties of selected strains were also investigated. The test strains exhibited lipolytic and proteolytic activities. They also tolerated low pH and survived satisfactory in gastric juice in vitro as well as in the presence of bile. In general, the isolates from faeces were more resistant to low pH and bile than those from Feta cheese. Selected strains could be used as starter supplements for industrial fermentations.