Kojic Acid from Aspergillus wentii: A Journey from Isolation to Application

Marine-derived fungi are widely known to produce a plethora of priceless biologically active secondary metabolites. The main objective of this study was to produce kojic acid as an exclusive secondary metabolite in the fermentation medium of Aspergillus wentii (MTCC 5374). Firstly, we describe the isolation of endophytic fungi from a marine alga followed by its growth- optimization in the laboratory to give maximum yield of kojic acid and finally its mass culturing for obtaining crude product. This paper also describes a simple, single-step extraction and column chromatographic purification of the crude extract to produce 98% pure kojic acid. Commonly used thin-layer chromatography (TLC) and advanced instrumentation techniques using NMR, IR and MS is reported for its easy identification. Kojic acid (5-hydroxy-2-hydroxymethyl-γ-pyrone) having a molecular formula C6H6O4 is a white, crystalline, water-soluble organic acid enzymatically produced from Aspergillus sp. It possesses potential application in the field of medicine, food, cosmetics and agriculture. Its outstanding application as a skin whitening agent by inhibiting formation of tyrosine is schematically represented assigning tyrosinase enzyme to act as a rate determining step in the production of melanin during hyperpigmentation.