Pigmentation and autofluorescence of Candida species after growth on tryptophan media

Abstract

Candida albicans and six other medically important Candida species were cultured on glucose–salts–biotin media containing tryptophan as the major nitrogen source. Candida albicans, C. tropicalis, and C. parapsilosis produced a pink pigment; C. krusei, C. pseudotropicalis, and C. gulliermondii formed brown pigments. Pigmentation of C. stellatoidea was variable, some strains produced brown pigments and others a pink pigment. Production of pink pigment was catalyzed by light. Cultures incubated in the dark produced only trace amounts of the pink pigment. Iron enhanced pigment production. Intense autofluorescence was observed for strains producing the brown pigment and weak autofluorescence for strains producing the pink pigment.