Improving Productivity of Bio Melanin Pigment Extracted from local Aspergillus Niger Isolate from Contaminated Dry Food Using Uv Method Mutagenesis

Abstract

This study explored the use of UV-C irradiation as a physical mutagen to enhance melanin biosynthesis in Aspergillus niger isolates.. Twenty-three fresh and dried food samples were collected, yielding twelve isolates of Aspergillus niger. Morphological identity was confirmed by amplifying the internal transcribed interstitial region (ITS) using polymerase chain reaction (PCR) with the generic primers ITS1–ITS4. Amplification was confirmed in 90% of the studied isolates. Melanin was extracted from the selected isolate and characterized using UV-Vis spectroscopy and Fourier transform infrared (FTIR) analysis. The native strain produced approximately 23 mg/g of melanin  of biomass. Genetic modification via mutagenesis was performed using UV-C (254 nm) irradiation at exposure distances of 5, 10, 15, 20, and 25 cm, and for durations of 30, 90, 180, 360, 540, and 720 seconds, respectively. The highest melanin yield (48 mg/g biomass) was obtained after irradiation for 360 seconds at a distance of 15 cm. These results demonstrate that UV-controlled mutagenesis is an efficient and economical approach for enhancing melanin production in Aspergillus niger.