Yellow Pigments of the Aspergillus niger Group

THE formation of yellow pigments by the A. niger group has been frequently reported. Frey1 reported two pigments : brown aspergillin and a golden-yellow pigment. Roussy2,3 reported the production of yellow pigments by this group in fatty media; but Pontillon4 showed that the pigment production was due to the removal of essential salts during the preparation of the medium. Lavollay and Laborey5–7 showed that growth on magnesium-deficient media produced riboflavin; Giordani8 had shown earlier that the yellow alkaline extract of A. niger spores had an adsorption spectrum similar to that of flavins, and Kitavin9,10 observed the formation of riboflavin on media containing small amounts of mercuric chloride. In a detailed study of forty-four strains, Knobloch and Sellman11 found twenty-two which produced yellow pigments; of these, twenty only produced pigments in the presence of reasonable quantities of magnesium, and another produced pigment with magnesium acetate as carbon source.