Alcoholic Fermentation of Platycodi Radix and Bioconversion of Platycosides Using Co-culture of Saccharomyces cerevisiae KCTC 7928 and Aspergillus awamori FMB S900

Abstract

The objectives of this study were to manufacture Platycodi radix (PR) wine, and assess the biotransformation pattern of PR platycosides using a co–culture of Saccharomyces cerevisiae KCTC 7928 with Aspergillus awamori FMB S900. The basal fermentation temperature was set to 15°C, and a high sucrose concentration (30% and above) was used to raise the level of ethanol production. The fermentation of PR by the co-culturing of S. cerevisiae with A. awamori was compared to that of a single culture of S. cerevisiae at concentrations of 30–50% (w/w) sucrose, and both types were analyzed at an interval of fifteen days during fermentation. The results showed that three major saponins (platycoside E, platycodin D3, and platycodin D) were converted into 16–oxo–PD during the co-culturing of S. cerevisiae with A. awamori while producing up to 12.5% ethanol (with an initial sugar concentration of 40%). The potential use of such a co–culturing system suggested an opportunity to develop PR wine with bioconverted platycoside.