Spectroscopic Characterization of Natural Melanin from a Streptomyces cyaneofuscatus Strain and Comparison with Melanin Enzymatically Synthesized by Tyrosinase and Laccase oleh Maher Al Khatib, Mohamed Harir, Jessica Costa, Maria Camilla Baratto, Irene Schiavo, Lorenza Trabalzini, Simona Pollini, Gian Maria Rossolini, Riccardo Basosi, Rebecca Pogni