Investigation of the effects of Elicitation and Quorum sensing on Monascus purpureus C322

Monascus purpureus, traditionally used in Chinese red yeast rice, is known for its production of lovastatin—a compound effective in reducing cholesterol—and various pigments (red, yellow, and orange). This study aims to enhance the production of these metabolites using biotic elicitors, such as oligomannuronate (OM), oligoguluronate (OG), and mannan oligosaccharides (MO) and quorum sensing molecules (farnesol, tyrosol, butyrolactone-I, linoleic acid) in M. purpureus C322. Fermentation processes were conducted in shaken flasks and scaled up to 2.5 L stirred tank bioreactors. Supplementation with elicitors and QSMs notably increased pigment and lovastatin production compared to control groups (p-value<0.01). Specifically, OG supplementation led to the highest increase in orange pigment production, achieving a 2.26 and 3.04-fold increase over control in flasks and bioreactors respectively. OM was most effective for enhancing yellow and red pigments, with increases of 2.03 and 2.6-fold in flasks, and 2.22 and 3.0-fold in bioreactors. OM also led to the highest lovastatin increases, with a 2.12 and 2.39-fold enhancement in flasks and bioreactors, respectively. Among quorum sensing molecules, farnesol showed the greatest impact, enhancing pigment yields with 1.87, 2.14, and 2.09-fold increase in yellow, orange, and red pigments in shaken flasks respectively. In bioreactors, the yield of yellow, red, and orange pigments increased by 2.11, 1.5, and 1.46-fold, respectively. Meanwhile, lovastatin production increased by 2.05-fold in flasks and a 2.39-fold increase in bioreactors. Genomic analysis of M. purpureus C322 revealed a 23.82 Mb genome across eight chromosomes, with the identification of several quorum sensing genes, such as Pho8, ADH1, PgpB, confirming the capability of M. purpureus C322 for quorum sensing. This research underscores the potential of elicitors and quorum sensing molecules for industrial applications and expands our understanding of the genetic and metabolic framework of M. purpureus C322.