Melanin and Bikaverin Production in F. verticillioides

Melanin pigments from each F. verticillioides mutant were extracted using a previously reported method [28 ]. The extracted pigments and synthetic melanin (Sigma-Aldrich, MO, USA) were then analyzed by using Fourier transform infrared (FT-IR) spectroscopy (Thermo Fisher Scientific, Warsaw, Poland) following the protocols described by Drewnowska et al [29 (link)]. To detect the production of bikaverin, each F. verticillioides strain was cultured at 25°C in PDB medium for 10 d. A 100 mL culture of each strain was extracted three times with ethyl acetate acidified with 1 mL of 25% HCl [30 (link)]. The samples were then analyzed on an HPLC–MS system (G2-XS QTof, Waters) using a protocol previously described [30 (link)].