Fermentation of Platycodi radix and bioconversion of platycosides using co-cultures of Saccharomyces cerevisiae KCTC 7928 and Aspergillus awamori FMB S900

Abstract

Preparation of Platycodi radix (PR) wine and assessment of biotransformation patterns of PR platycosides using co-cultures of Saccharomyces cerevisiae KCTC 7928 with Aspergillus awamori FMB S900 were performed. The basal fermentation temperature was 15°C and a high sucrose concentration (30% and above) was used to increase the level of ethanol production. Fermentation of PR in co-cultures of S. cerevisiae with A. awamori was compared to single culture fermentations using S. cerevisiae at concentrations of 30–50% (w/w) sucrose with analysis at an interval of 15 days during fermentation. The 3 major saponins (platycoside E, platycodin D3, and platycodin D) were converted into 16-oxo-PD during co-cultures of S. cerevisiae with A. awamori with production of up to 12.5% ethanol (with an initial sugar concentration of 40%).