Effect of Humic Substances on Fungal Melanin Formation

Fungal pigment melanin play a special role in hypotheses of soil humification processes, being debated as precursors of soil humic substances (HS) due to their similarities in many properties. This fact generated discussions about their mutual transformations. The objective of this study was to analyze the influence of HS on formation and composition of dark-colored fungal pigments. The pure culture of melanin-containing micromycete Cladosporium cladosporioides was cultivated with and without addition of potassium humate. Fungal biomass was determined, melanin was extracted from mycelium and analyzed using 13C NMR spectroscopy. The obtained data allowed assuming that HS can modify the melanin structure of Cladosporium cladosporioides and probably change the way of fungal melanin synthesis.