Extraction and Characterization of Kojic Acid from Aspergillus flavus

Ten days cultures of A. flavus ASU45 growing on the optimum modified Czapek’s glucose broth medium were filtrated, centrifuged at 5000 xg for 10 min., and extracted using ethyl acetate (1:1, filtrate: solvent). KA was measured according to Sanjotha et al. [13 ] by ferric chloride reagent at 540 nm using a spectrophotometer. For crystallizing KA; ethyl acetate extracts were stored for 1 day at 5 °C, then evaporated using a rotatory evaporator at 70 °C (120 rpm), and then KA crystals were removed in clean filter paper until complete drying [52 (link), 54 ]. Kojic acid crystals were characterized using FTIR, XRD, and scanning electron microscope. IR spectral data were revealed in spectrophotometer type Nicolet iS10 (4000–500 cm⁻¹), PXRD pattern was revealed in the 2θ range of 10–80° via Philips PW 1710 X-ray diffractometer working at 40 kV and 40 mA (λ = 1.54060A°) equipped with nickel filtered CuKα radiation. Kojic acid crystals were photographed by scanning electron microscopy (SEM) (JSM 5400 LV; JEOL, Japan).