High-throughput screening to improve the yield of Monascus red pigment from Monascus purpureus

Monascus red pigment is a natural pigment produced by Monascus purpureus, known for its high medicinal and nutritional value. To enhance the yield of Monascus red pigment in liquid fermentation, ARTP mutagenesis was applied iteratively to M. purpureus LBBE. A high-throughput screening method was developed based on double-dye fluorescent labelling, flow cytometry sorting, microplate solid-state culture, and other advanced techniques to improve the screening efficiency. Through ten rounds of iterative mutagenesis and high-throughput screening, a total of 24,000 mutants were analyzed, ultimately leading to the identification of the high-yield strain LBBE-29. Shake flask fermentation demonstrated that the Monascus red pigment color value of LBBE-29 reached 1,117.6 U·mL^− 1, which was 2.03 times higher than that of the starting strain while maintaining strong genetic stability. This high-throughput screening method not only provided an effective approach for the mutagenesis breeding of M. purpureus strains with enhanced pigment production but also served as a theoretical reference for high-throughput mutagenesis breeding of other filamentous fungi.