Melanin from marine Streptomyces sp. (MVCS13) with potential effect against ornamental fish pathogens of Carassius auratus (Linnaeus, 1758)

Melanin pigments were extracted from a wide variety of microorganisms including bacteria and fungi. In the present study isolation, identification and characterization of melanin from marine actinobacterium (Streptomyces sp. MVCS13) and its potential activities against fish pathogens were investigated. Culture conditions and medium composition for the melanin production were optimized. Further, pigment was characterized by UV-vis absorption spectroscopy and FT-IR infrared spectrometry. It has potential antibacterial activity against ornamental fish pathogens Vibrio sp. FPO5 (15±0.01 mm) followed by Aeromonas sp. FPO6 (12±0.02 mm) which was isolated from Carassius auratus infected fish. The minimum inhibitory concentration (MIC) ranges were observed between 18±0.01 and 27±0.03 μg/ml. The present study suggested that, on the basis of anti-bacterial activity and MIC test of melanin pigment from Streptomyces sp., MVCS13 can be selected as an effective anti-bacterial agent for ornamental fish culture.