A bacterium designated as a Klebsiella oxytoca ISA4 was isolated from oil-contaminated soil; it not only is unable to catabolize dibenzothiophene as a sole source of carbon and energy but also produces biosurfactant. In order to enhance the efficiency of biodesulfurization, the dszABC genes from Rhodococcus erythropolis IGTS8 were amplified by specific primers. PCR ampilicon of 3.8 kb was obtained and cloned using pVLT31 vector in native K. oxytoca ISA4. Further analysis by Gibbs assay and gas chromatograph revealed that recombinant K. oxytoca ISA4 has the highest desulfurization ability (48%) in comparison with R. erythropolis IGTS8 (42%) and Pseudomonas aeruginosa pTSOX4 (46%).