Use of agar as carrier in solid-state fermentation for Monacolin K production by Monascus: A novel method for direct determination of biomass and accurate comparison with submerged fermentation

•A novel solid-state fermentation process by using agar as carrier was developed.•The novel system was successfully used for production of Monacolin K by Monascus.•Monacolin K production reached 2047 mg/L in SSF, 4.47 times as much as that of SmF.•It was feasible for direct determination of biomass and comparison with SmF.

For the first time, a novel solid-state fermentation (SSF) process by using agar as carrier was developed and it was feasible for direct determination of fungal biomass and accurate comparison with submerged fermentation (SmF). Specifically, this novel system was successfully applied for the production of Monacolin K by Monascus purpureus. Results showed that the optimal agar concentration, particle size and glycerol concentration were 4%, 4 mm × 4 mm × 4 mm and 18%, respectively, in which the Monacolin K production reached 2047.03 mg/L, 4.47 times as much as that of SmF. The comparative time course study showed that the biomass accumulation, MK biosynthesis and glycerol consumption in SSF were more rapid than that of the SmF.

Graphical abstractTime course of microbial growth and Monacolin K synthesis by Monascus purpureus during solid-state fermentation and submerged fermentation.Figure optionsDownload full-size imageDownload as PowerPoint slide