Petroleum energy is the major source of the world energy market, and its massive usage, and the corresponding extreme environmental pollution, imposes a serious threat on the ecological cycles. By screening oil-contaminated soil, we isolated, identified, and characterized a novel strain that represents a considerable diesel-degrading potentiality; the Bacillus aryabhattai DA2 strain is registered in the NCBI with the accession number MG571630, and it possesses an efficient tributyrin-degrading capacity. The optimal condition for diesel degradation by DA2 strain was observed at pH between 7-8 and at the temperature of 30°C. The strain is resistant to salt as well as the antibiotics like ampicillin and streptomycin. These results indicate B. aryabhattai is one of the potential candidates for the remediation of the diesel-contaminated sites.

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.