# Pigment Formation by Monascus pilosus DBM 4361 in Submerged Liquid Culture

## TL;DR

This study explores how Monascus pilosus produces different pigments in liquid culture, revealing new patterns and optimal conditions for pigment formation.

## Contribution

The study identifies novel pigment formation patterns and optimal nutrient conditions for M. pilosus in submerged culture.

## Key findings

- M. pilosus produces yellow pigments like monascuspiloin in submerged culture.
- Glucose and ammonium sulfate repress pigment formation in SLC.
- Optimal yellow pigment concentration reached 340 mg/L using sucrose and tryptone.

## Abstract

Monascus pilosus is usually
cultivated
on rice because of monacolin K. We focused on pigment production in
submerged liquid culture (SLC) where M. pilosus produced different pigments compared to M. purpureus and M. ruber. From the group of classic Monascus pigments, there were formed mostly compounds
with a five-carbon side chain, and the dominant pigment was monascuspiloin,
a yellow pigment structurally similar to monascin. In SLC, previously
undescribed patterns affecting pigment formation were observed, such
as the Crabtree effect, carbon catabolite repression of pigments caused
by glucose and other mono-/disaccharides, as well as nitrogen regulation,
particularly repression of pigment formation by ammonium sulfate.
The highest pigment concentration in the extract was obtained using
an organic nitrogen source, specifically 340 mg/L for yellow pigments
utilizing a combination of sucrose and tryptone, 346 mg/L for orange
pigments using starch and tryptone, and 75 mg/L for red pigments using
lactose and tryptone.