Results of investigations on the biosolubilization of a low-rank coal, viz. lignite (fromNeyveli, TamilNadu, India), into humic acid are reported in the present paper. Solubilizationwas effected at ambient temperature and pressure, employing two bacterial strains isolated from Neyveli lignite mines. The bacterialmicrobeswere isolated, characterized and studied under controlled conditions for their efficacy to solubilize the lignite. The results evince that of the two isolated bacterial strains, Bacillus sp. showed maximum (4.2%, w/w) solubilization, whereas the other one, viz., Bacillus licheniformis, exhibited comparatively less solubilization, 3.3%(w/w). The solubilization process was studied in respect of such parameters as media, initial pH, incubation period, and substrate concentration.Aplausiblemechanism of the solubilization by bacterial species is suggested.