Halotolerant black yeast Neophaeotheca triangularis as a source of melanin

Archaea and bacteria are the most studied extremophiles, but fungi also demonstrate remarkable tolerance, particularly in hypersaline environments such as solar salterns. Among salt-adapted fungi, black yeasts have been shown to be adapted to such environments, having developed defense mechanisms such as the production of melanin, a pigment that plays a crucial role in environmental stress protection. Melanin is a complex, high-molecular-weight polymer widely found across biological kingdoms. During the isolation of microorganisms from samples collected in crystallization ponds in a saltern, a black yeast was found able to produce significant amounts of melanin. The yeast was identified as belonging to the species Neophaeotheca triangularis. The aim of this study was to optimize the cultivation conditions of the strain, to characterize the produced melanin, and to assess its biological activities, including its antitumor and antioxidant properties.