Pigment Production, Purification, and Characterization from Endophytic Fungal Isolate Fusarium foetens N7

Abstract

In the previous century, the extensive use of synthetic pigments through a myriad of industries instigated concerns about their deleterious health and environmental outcomes. Scientific breakthroughs have since provoked a revolution towards natural pigments, notably those showcasing beneficial pharmaceutical properties, sourced primarily from microbial organisms. Endophytic fungi, known for their prolific secondary metabolite production, stand out as promising candidates for generating such pigments. In the present study, on screening an endophytic fungal isolate Fusarium foetens N7 was selected based on its pigment-producing ability. Fungal isolate N7 produced intracellular pigment in potato dextrose media. The color of the crude pigment was reddish-purple. It was extracted by using ethyl-acetate. The extracted pigment was observed for its antimicrobial and cytotoxic properties. It was purified by Normal Phase Column Chromatography and then purified pigmented fractions were observed for antimicrobial and antioxidant properties. The purified pigmented fractions were characterized by Thin Layer Chromatography (TLC), Fourier Transformer Infrared Spectrophotometer (FTIR), and Gas Chromatography-Mass Spectrometry (GC-MS). The result of FTIR and GC-MS analysis showed that the pinkish-purple band of F-1 may be naphthoquinone from polyketide. The cytotoxicity results showed that the pigment prevented 77 % of the lysis of human erythrocytes against Sodium Dodecyl Sulfate (SDS) and hence, the compound is non cytotoxic. The antimicrobial potential of purified pigmented fractions showed that the dark orange fraction (F-1) demonstrated the highest antibacterial activity with a 42 mm zone of inhibition against Staphylococcus aureus and a 31 mm zone of inhibition against Candida albicans. The maximum antioxidant activity was reported by the orange-brown fraction (F-2) to be 72% against DPPH. Therefore, it can be demonstrated that due to the pronounced bioactive potential and non-toxic nature, the extracted pigment from Fusarium foetens N7 can find applications in the food and pharmaceutical industry