Isolation, Purification and Melanin Synthesis Pathways in Aspergillus Section Nigri

Background: Melanin is a ubiquitous, dark polymeric pigment found naturally in plants, animals and microbes. The current study looked into the quantity and kind of melanin created by eight isolates belonging to the Aspergillus section Nigri: A. awamori, A. brasiliensis, A. costaricaensis, A. luchuensis, A. piperis, A. niger, A. tubingensis and A. welwitschiae. Material and methods: Soil samples were collected from seven locations within Basrah Province. Species identification was performed through sequencing of ITS region and β-tubulin gene. The isolates were cultured on CDA and L-tyrosine PDA, and incubated for ۷, ۱۴ and ۲۱d for melanin extraction. qualitative and quantitative of melanin characterization were done using UV–Vis spectroscopy, Fourier- transform infrared spectroscopy and scanning electron microscopy. The biosynthetic pathway of melanin was investigated by applying the pathway inhibitors kojic acid and difenoconazole. Results: results indicate that A. niger produced the highest melanin yield after incubating on L-tyrosine PDA for ۳ wk. The ۳,۴-dihydroxyphenylalanine pathway was identified in A. niger and A. brasiliensis, whereas the ۱,۸-dihydroxynaphthalene pathway was active across all tested species. Conclusion: The study revealed interspecies differences in the type and quantity of melanin produced among Aspergillus section Nigri isolates.

کلیدواژه ها:

Aspergillus section Nigri ، DOPA-melanin ، DHN-melanin ، kojic acid ، difenoconazole.