Explain Monascus species

Most of the reports of food colourants from microbial sources involve Monascus species, particularly Monascus purpureus, followed by  Rhodotorula species,  Chlorella,  Nocardia and red algae. Often, instead of extracting the pigment from Monascus, a few researchers have attempted in adding the whole coloured substrate to foods for the purpose of providing colouration. Careful control of the culture conditions selectively improves the yield of various pigments elaborated by the specific microbial culture.