石油および環境バイオテクノロジージャーナル

概要

Plasmid Curing of a Novel Hydrocarbon Degrading Bacillus cereus Strain DRDU1 Revealed its Involvement in Petroleum Oil Degradation

Debajit Borah* and Yadav RNS

Plasmid curing of a novel hydrocarbon degrading Bacillus cereus strain DRDU1 was carried out to confirm the possible involvement of plasmid genes in hydrocarbon degradation. Plasmid curing was done by using 100 μg/mL of ethidium bromide, which is approximately 12 kb in size. Hydrocarbon degradation potential of the plasmid cured strain was compared with that of the control and the percentage hydrocarbon degradation of diesel, kerosene, crude oil and used engine oil after 28 days of incubation was confirmed by gas liquid chromatographic (GLC) analysis. The percentage hydrocarbon degradation for diesel, kerosene, crude oil and used engine oil (2% v/v) in Bushnell and Haas (BH) broth was found to be decreasing up to 30%, 21%, 13%, and 6% respectively for the plasmid cured strain, from its initial values of 99%, 96%, 84%, and 29% by the uncured strain. This study clearly confirms that the respective petroleum hydrocarbon degradation in this case is both plasmid and chromosomal encoded as considerable amount of degradation can be seen by the plasmid cured strain also. Due to this the strain is beneficial for in-situ bioremediation purpose, as the loss of plasmid due to any environmental or biological factor will not stop its potential to degrade hydrocarbon oil.