This study aimed at investigating the application of biosurfactant from Sphingobacterium spiritivorum AS43 using molasses as a substrate and fertilizer to enhance the biodegradation of used lubricating oil (บนว). The cell surface hydrophobicity of bacteria, the emulsification activity, and the biodegradation efficiency of บLO were measured. The bacterial adhesion in the hydrocarbon test was used to denote the cell surface hydrophobicity of the used bacterial species. The results indicate a strong correlation between ccll surface hydrophobicity, emulsification activity, and the degree of ULO biodegradation. The maximum degradalion of ULO (62 %) was observed when either 1.5 %(พ/v) of biosurfactant or fertilizer was added. The results also revealed that biosurfactants alone are capable of promoting biodegradation to a large extent without added fertilizer. The data indicate the potential for biosurfactant production by using low-cost substrate for application in the bioremediation of soils contaminated with petroleum hydrocarbons or oils.