Tween 80 (polyoxyethylene sorbitan monooleate), Triton X-100 (non-aethylene glycol octylphenol ether), and SDS (sodium dodecyl sulfate) solubilized several components of Mississippi Wilcox lignite and Illinois No. 6 bituminous coal. Tween 80 extraction of alkali-soluble Ugljevik lignite resulted in an increase in hydrogen content and decreases in the nitrogen and sulfur contents of undissolved coal solids. Biosurfactant-containing cell-free extracts of Bacillus licheniformis solubilized a 53 000 Da coal component of Mississippi Wilcox lignite. The results suggest that solubilization of coal organic components by chemically- and biologically-synthesized surfactants has potential in terms of upgrading coals.