ABSTRACT
The term "liquefaction" denotes a changing of a solid to a liquid; thus the use of "bioliquefaction" of coal would imply a direct conversion from solid to liquid coal, the latter which might or might not be hydrophilic. Recent efforts in coal bioconversion research have focused on pretreatments of biorecalcitrant coals to enhance microbial activity and on characterization of the solubilized product. A direct correlation between coal biosolubility and solubility in dilute alkaline buffer, and between coal oxygen content and either biosolubility or alkali solubility has been established. Nonoxidizing pretreatments with hydrochloric acid have been used to enhance biosolubility of a variety of coals. This chapter describes general methods for isolating from natural sources a variety of coal-solubilizing strains of fungi and bacteria. It presents examples of application of methods for semiquantitative and quantitative biosolubility assays on a variety of coals, including some high-ranked coals pretreated to enhance biosolubility.
