Potential probiotic and food protection role of wild yeasts isolated from pistachio fruits (Pistacia vera)

BACKGROUND The biotechnological potential of yeasts from nuts such as pistachio, not only for health applications but also for industry use, has been scarcely studied. Interest in the probiotic capability of yeasts has increased in the past years as well as their utilization as food or feed preservatives. Their capabilities as biocontrol against problematic (spoilage or toxigenic) microorganisms or as antioxidants have been revalued. As a result, both abilities would be desirable to develop a new potential probiotic microorganism which could be added to food or feed to improve their properties. RESULTS Molecular techniques allowed the identification of a total of seven different species and 15 strains. A screening of the probiotic potential of these strains was carried out. It was found that 65% of the strains resisted the gastrointestinal conditions as well as presented a generation time of < 22 h. Additionally, some strains showed better kinetic parameters thanSaccharomyces boulardii(positive control). Complementary tests were done to determine their auto-aggregation capacity, cell surface hydrophobicity, behaviour in a sequential simulated digestion, biofilm formation capability and carbon source assimilation. Finally, 67% and 13% of the studied yeasts showed biocontrol and antioxidant activities, respectively. CONCLUSIONS Diutina rugosa14 followed byDiutina rugosa8 were the best wild yeast fromPistacia veraas potential probiotic and in carbon source utilization. However,Hanseniaspora guilliermondii6 andAureobasidium proteae5 could be used to improve food or feed product preservation because of their notable biocontrol and antioxidant capabilities. (c) 2020 Society of Chemical Industry

Automated summary

Molecular techniques were used to identify seven different species and 15 strains of yeasts from pistachios. Screening showed that 65% of the strains had probiotic potential and could resist gastrointestinal conditions with a generation time of <22 hours. Some strains even outperformed the positive control Saccharomyces boulardii. Additional tests revealed their capabilities in auto-aggregation, cell surface hydrophobicity, simulated digestion, biofilm formation, and carbon source assimilation. 67% and 13% of the studied yeasts showed biocontrol and antioxidant activities.