Investigation on screening, identification, and fermentation characteristics of Yunnan olive in the fermented liquid utilizing five strains of Saccharomyces cerevisiae

Refined indigenous Saccharomyces cerevisiae can enhance refinement, sophistication, and subtlety of fruit wines by showcasing exceptional regional characteristics. In order to identify exceptional indigenous S. cerevisiae strains from Yunnan olive, this study isolated 60 yeast strains from wild Yunnan olive fermentation mash. The five S. cerevisiae strains were subjected to morphological and molecular biological identification, followed by evaluation of their fermentation performance, ethanol production capacity, ester production capacity, H₂S production capacity, killing capacity, and tolerance. Strains LJM-4, LJM-10, and LJM-26 exhibited robust tolerance to 6% ethanol volume fraction, pH 2.8, sucrose concentration of 400 g/L, SO₂ concentration of 0.3 g/L, glucose concentration of 400 g/L at both 40 °C and 15 °C. Additionally, strain LJM-10 demonstrated a faster fermentation rate compared to the other strains. Among the tested S. cerevisiae strains evaluated in this study for olive wine fermentation process in Yunnan region; strain LJM-10 displayed superior abilities in terms of ester and ethanol production while exhibiting the lowest H₂S production levels. These findings suggest that strain LJM-10 holds great potential as an excellent candidate for optimizing fruit wine S. cerevisiae fermentation processes in Yunnan olive fruit wine.