Use of chemical pretreatment agents on the subsequent enzymatic conversion of coal is described. As an example, fungal manganese peroxidase (MnP) produced by the agaric white-rot fungus Bjerkandera adusta, where the enzyme MnP has little effect on the untreated coal controls, was investigated. The nature of pretreatment agents and their applied concentrations were found to have significant impact on subsequent enzymatic conversion of coal. Four agents were investigated: HNO.sub.3, catalyzed H.sub.2O.sub.2, KMnO.sub.4, and NaOH. Hydrogen peroxide was found to generate the greatest quantity of total organic carbon from the coal samples employed. Combined chemical and enzymatic treatment of coal is appropriate for enhanced depolymerisation of coal and coal-derived constituents and results in chemically heterogeneous and complex liquefaction products like humic and fulvic acids, which will have important ramifications in the generation of liquid and gaseous fuels from coals as nonpetroleum-derived fuel alternatives.
STATEMENT REGARDING FEDERAL RIGHTS
 This invention was made with government support under Contract No. RPSEA 07122-14 awarded by the Research Partnership to Secure Energy for America to The Regents of The University of Wyoming. The government has certain rights in the invention.