Isolation and identification of pigment-producing filamentous fungus DBFL05 and its pigment characteristics and chemical structure

Natural pigments derived from microorganisms have many advantages and are widely studied in the food industry. A filamentous fungus, DBFL05, was identified as Aspergillus ustus, which produces a bright abundant brown pigment. This extracellular, water-soluble pigment is highly polar slightly soluble alcohol but insoluble other organic solvents. The stable under sunlight, at pH 2–10, below 100°C. However, it sensitive to Zn2+, Fe3+, Fe2+, Cu2+. mainly composed of two chemical components, pyrropyrazine diketone dianthrone, classified polyketone Both components exhibit inhibitory effects on bacteria scavenging abilities for •OH DPPH. showed no significant toxicity plants low brine shrimp larvae. These findings indicate that easily obtainable A. ustus with attractive colour, stability, safety, bioactivity.