Functional Verification of Transcription Factor comp54181_c0 in Monascus purpureus

ABSTRACT Monacolin K is a valuable secondary metabolite produced after a period of fermentation by Monascus purpureus ; however, our current understanding of the regulatory mechanisms of its synthesis remains incomplete. This study conducted functional analysis on the key transcription factor, comp54181_c0, that is involved in the synthesis of monacolin K in Monascus . Mutant strains with either knockout or overexpression of comp54181_c0 were constructed using CRISPR/Cas9. A comparison between the knockout and overexpression strains revealed changes in fungal morphology and growth, with a significant increase in the production of Monascus pigments and monacolin K when comp54181_c0 was absent. Real‐time fluorescence quantitative PCR analysis revealed that comp54181_c0 significantly influenced the transcription of key genes related to monacolin K biosynthesis in Monascus . In conclusion, our study elucidates the crucial role of comp54181_c0 in Monascus , enriches our understanding of fungal secondary metabolite development and regulation, and provides a foundation for the development and regulation of Monascus and monacolin K production.