Effect of Exogenous and Endogenous Ectoine on Monascus Development, Metabolism, and Pigment Stability

Monascus, a key player in fermented food production, is known for generating Monascus pigments (MPs) and monacolin K (MK), possessing bioactive properties. However, the limited stability of MPs and mycotoxin citrinin (CTN) constrain the Monascus industry. Extremolytes like ectoine, derived from bacteria, exhibit cytoprotective potential. Here, we investigated the impact of ectoine on Monascus purpureus ATCC 16365, emphasizing development and secondary metabolism. Exogenous 5 mM ectoine supplementation substantially increased the yields of MPs and MK (105%-150%) and reduced CTN production. Ectoine influenced mycelial growth, spore development, and gene expression in Monascus. Remarkably, ectoine biosynthesis was achieved in Monascus, showing comparable effects to exogenous addition. Notably, endogenous ectoine effectively enhanced the stability of MPs under diverse stress conditions. Our findings propose an innovative strategy for augmenting the production and stability of bioactive compounds while reducing CTN levels, advancing the Monascus industry.

Automated summary

In this study, the supplementation of exogenous ectoine effectively increased the production of Monascus pigments (MPs) and monacolin K (MK), while reducing citrinin (CTN) levels in Monascus purpureus. Moreover, the endogenous ectoine biosynthesis in Monascus showed comparable effects to exogenous addition, enhancing the stability of MPs. These findings propose an innovative strategy to improve the production and stability of bioactive compounds, and reduce CTN levels, advancing the Monascus industry.