Multiomics comparative analysis reveals the role of carbon metabolism in enhancing monascin and ankaflavin production in Monascus purpureus

Abstract

The genus Monascus is widely used in the pharmaceutical and food industries for the production of monascin, ankaflavin, and related compounds. The contents of monascin and ankaflavin in red-yeast rice are low, thus revealing that the synthesis mechanisms of these compounds can significantly improve their synthesis efficiency. Here, two high-quality genomes of the original M. purpureus and UV mutants with higher monascin and ankaflavin contents were assembled and annotated as 24.63 Mb and 24.62 Mb, respectively, and contained 8279 and 8360 genes. Integrated genome and transcriptome analysis revealed 573 variant genes and 625 differentially expressed genes (DEGs) between the two M. purpureus strains. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that these genes were most closely related to fatty acid and carbon metabolism, which can provide more precursors for the biosynthesis of monascin and ankaflavin. Furthermore, overexpression of the variant gene wrbA related to carbon metabolism in the original M. purpureus strain promoted monascin and ankaflavin production, with increases of 25.6 % and 8.5 %, respectively. Our study also confirmed that the UV mutagenesis strains fermented with red-yeast rice had a greater ability to inhibit intracellular lipid accumulation. Our results revealed that the sequence and expression profiles of genes involved in carbon metabolism, such as wrbA, which can contribute to monascin and ankaflavin biosynthesis and accumulation, changed during UV-induced M. purpureus infection.