Production and Characterization of Melanin Pigment from Halophilic Black Yeast Hortaea werneckii

Melanin is nearly a ubiquitous pigment synthesized by living organisms in the course of hydroxylation and polymerization of organic compounds. Melanins have immense application potentials in the field of agriculture, cosmetics and pharmaceutical industries (photoprotection and mosquitocidal activity isolated from Streptomycete). In this study, the halophilic black yeast, Hortaea werneckii produced a diffusible dark pigment on potato dextrose agar. This work was designed to study the ability of the yeast for the production, characterization and optimization of the melanin pigment with different nutrient sources. Characterization of melanin was analyzed by UV spectroscopy, FT IR, SEM and antibacterial potential of melanin was also studied. The favorable condition for the high yield of melanin was found to be glucose as carbon source and peptone as nitrogen source with the optimum parameters like temperature 30oC, salinity 15‰, pH 7.0, incubation period of 168 hrs and the rice bran as a cheaper substrate, which produced 5.60g/L of melanin. It also showed inhibitory activity against potential pathogens and activity was observed in Salmonella typhi (17mm) and Vibrio parahaemolyticus (15mm). It was concluded that the melanin of Hortaea werneckii isolated from solar salterns possess a high antibacterial activity and could act as a suitable source of new antimicrobial natural products.