Kojic Acid Inhibition of Aspergillus Melanization

Kojic acid (Sigma-Aldrich, Bangalore, India), an inhibitor of tyrosinase, was used to inhibit the l-DOPA pathway of melanization in A. flavus. A mycelial plug of 5-mm diameter was inoculated into a Petri dish containing the PDA culture medium with or without Kojic acid (dissolved in 70% dimethyl sulfoxide (DMSO) in different concentrations ranging from 100 to 5 mg/ml. Plates were incubated for 10 days at 30 °C, the growth and pigmentation were recorded as described earlier (Pal et al. 2014 (link)). The minimum inhibitory concentration (MIC) values of Kojic acid for three A. flavus strains were also determined. After 10 days of incubation, dry conidia were collected and used for further experiments.