Cell-Free Solubilization of Coal by Polyporus versicolor.

Solubilization of coal was demonstrated with filtrates (0.45-mum-pore-size filters) obtained from the broth in which Polyporus versicolor had grown. The rate and extent of solubilization were dependent on the age of the fungal cultures, the particle size of the coal, the pH of the filtrates, and the presence of proteins in the filtrates. The rate of solubilization of coal was significantly reduced after proteins in the filtrates were denatured by acid hydrolysis.