[Effect of cyclic compounds on pigment formation in Aspergillus niger cultures].

The mycelial pigment os Asp. niger VP has been fractionated into four fractions ehose solubility is similar to melanin pigments obtained from other sources. The addition of pyrocatechol, L-aspartic, benzoic, kojic and salicylic acids to the liquid Capek medium stimulates the fungal growth but diminishes the yield of fractions of the melanin pigment from the mycelium. Cinnamic acid does not influence the growth but also decreases the yield of the pigment. DL-tyrosine stimulates the fungal growth and produces no influence on the total yield of fractions 2, 3 and 4 from the mycelial pigment. All the cyclic compounds enhance the pigmentation of the culture liquid and give rise to the formation of fractions 2 and 3 of the melanin pigment. This latter constitutes a substantial portion of the dry matter of the fungal cell. The pigment content in the mycelium is much higher than that in the culture liquid of the corresponding culture.