The petroleum industry is an important part of the world economy. However, the massive exposure of petroleum in nature is a major cause of environmental pollution. Therefore, the microbial mediated biodegradation of petroleum residues is an emerging scientific approach used to resolve these problem. Through the screening of diesel contaminated soil we isolated a rapid phenanthrene and a diesel degrading bacterium identified as Enterobacter cancerogenus DA1 strain through 16S rRNA gene sequence analysis. The strain was registered in NCBI with an accession number MG270576. The optimal growth condition of the DA1 strain was determined at pH 8 and 35°C, and the highest degradation rate of the diesel was achieved at this condition. At the optimal condition, growth of the strain on the medium containing 0.05% phenanthrene and 0.1% of diesel-fuel was highest at 45 h and 60 h respectively after the incubation period. Biofilm formation was found significantly higher at 35°C as compared to 30°C and 40°C. Likewise, the lipase activity was found significantly higher at 48 h after the incubation compared to 24 h and 72 h. These results suggest that the Enterobacter cancerogenus DA1 could be an efficient candidate, for application through ecofriendly scientific approach, for the biodegradation of petroleum products like diesel.

Abstract
 INTRODUCTION
 MATERIALS AND METHODS
  1. Isolation of diesel degrading bacteria in crude oil
  2. Identification of Bacteria
  3. Characterization of phenanthrene degradingstrains
  4. Optimal test conditions for phenanthrenedegradation
  5. Phenanthrene quantification
  6. Biofilm formation assays
  7. Lipase production
  8. Lipase assay
  9. Effect of incubation time and temperature onlipase activity
  10. Statistical analysis
 RESULTs AND DISCUSSION
  1. Isolation, identification and characterization ofoil-degrading microorganisms
  2. Determination of optimal stage of degradation
  3. Biofilm production
  4. Determination of lipase production
 CONCLUSION
 REFERENCES

• Sang-Jun Kim(Department of Natural Sciences, Naval Academy)
• Gil-Jae Joo(Institute of Agricultural Science and Technology, Kyungpook National University) Corresponding author