Production of water-soluble melanin pigment by marine derived Penicillium citrinum 2332 occurring as a sponge endosymbiont

Abstract

Melanin pigments are dark coloured and made of heterogeneous polymers of phenolic and/or indolic monomers and are produced by a wide range of organisms, including fungi. Although melanins are insoluble, pyomelanin is water-soluble and is endowed with antimicrobial, antioxidant, and anti-inflammatory properties. These features, along with their UV-screening ability, enhance the ecological fitness of pyomelanin-producing organisms. Most studies on microbial pyomelanin are focused on bacteria, and there are very few studies on fungal pyomelanin. The present study reports for the first time, that a marine-derived isolate of Penicillium citrinum 2332 isolated as an endosymbiont of a marine sponge, produces this technologically useful pigment.