Isolation, Screening and Identification of Yeasts for Alcoholic Fermentation of Bergamot Vinegar

Abstract:

Yeasts with good characteristics are important for the alcohol fermentation in bergamot vinegar production while limonin in bergamot will inhibit the yeast growth. This study aimed to screen yeast strains with favorable characteristics in bergamot fermentation based on the unique properties of bergamot. Eighty five yeast strains were screened from natural fermented bergamot juice and the yeast strain named FS-ZJQ with good ethanol and organic acids production ability was selected through a three step screening method. Strain FS-ZJQ was identified as Saccharomyces cerevisiae in taxonomy through 18S rDNA sequencing and it showed strong ability to tolerate sugar, pH and alcohol. This strain could produce 8.49% alcohol in 18 °Bx bergamot juice when fermented at 25 ℃ for 7 d. High contents of terpenoid and ester compounds were observed in bergamot wine, which accounted for 58.83% and 16.44% of the total volatile compounds. After acetic fermentation, the content of non-volatile acids reached 5.06 mg/mL.