Orange-Brown Pigment Production from an Endophytic Fungus Aspergillus Sp. N11 and its Potential Pharmaceutical Applications

Abstract Endophytic fungi are the main source of natural compounds including pigments having various industrial applications. Present study describes the production of extracellular orange-brown pigment from an endophytic fungal isolate Aspergillus sp. N11from Teucrium stocksianum. The optimum conditions for pigment production from this isolate was investigated and results showed that highest yield was observed in Potato dextrose broth, at pH 5 and 30 ℃ under shaking condition at 150 rpm for 7-10 days. The pigment was extracted in ethyl acetate and purified using column chromatography. Three different pigments were purified (yellow, light brown and orange-brown) and characterized based on Thin layer chromatography and Fourier transform infrared spectroscopy. The antimicrobial activity of purified fragments showed maximum zone of inhibition of 40 mm against S. aureus while for P. aeruginosa maximum zone of 50 mm and maximum antifungal activity of 20 mm against C. albicans. The antioxidant potential of purified pigment obtained from Aspergillus sp. N11 indicates that maximum scavenging activity of 67%. The results showed that purified pigments are astaxanthins belonging to oxygen containing carotenoids. The purified astaxanthins showed antibacterial, antifungal and antioxidant activities indicating its potential to be utilized in pharmaceutical and food industries.