Melanin from Marine Actinobacteria and Its Medical Applications

Melanin pigment is widely distributed in humans, animals, plants, and microorganisms and plays various protective and immune-regulatory roles. Among microbial pigments, melanin is considered very important due to its distinctive physical, chemical, and biological characteristics, including hydrophobicity, high molecular weight, and a negative charge. Actinomycetes from the marine ecosystems can produce pigments and secondary metabolites of pharmaceutical value. Members of the phylum Actinobacteria, chiefly Glycomyces and Streptomyces genera, can generate high volumes of bioactive compounds, contributing significantly to the pool of industrially and medically relevant metabolites. Actinobacteria produce nearly two-thirds of naturally occurring bioactive microbial products, which are effective against multidrug-resistant pathogens. Although research on marine actinomycetes is still an ongoing process, their potential as a major source of melanin and other secondary metabolites highlights their considerable biotechnological and pharmaceutical significance.