Biotransformation of powdered hard coal and its organic extract was ac
hieved by means of Piptoporus betulinus, Nocardia rubra and Pseudomona
s aureofaciens in aqueous medium. The process of depolymerization was
evaluated on the basis of chromatographic and spectral data. Gas chrom
atograms, high-performance size exclusion chromatograms and u.v., i.r.
and H-1 n.m.r. spectra are discussed.