Improvement of flavour compound synthesis in a mixed culture system at high temperature by solid-state fermentation

In order to enhance the synthesis of flavour compounds in solid-state fermentation (SSF) at a high temperature, Bacillus subtilis XJ-013 and Saccharomyces cerevisiae Z-06 were used as a mixed culture with Monascus HQ-3. The culture temperature was enhanced from 37°C to 56°C by the synergetic effect, and the synthesis of esterase was enhanced from 85.43 U/g to 129.65 U/g in the mixed culture system (over 50% higher than that of the culture using a single strain). This resulted in the synthesis of favourable flavour compounds in the solid-state fermentation. These results signified that a mixed culture of Monascus and S. cerevisiae was favourable for enzyme production. The mixed culture of Monascus and B. subtilis resulted in a high culture temperature that promoted flavour compound synthesis in the solid-state fermentation system dramatically. These results present a model to explain the synergetic effects between the fungus and the Bacillus in the solid-state fermentation.