Biodegradation of Petroleum Oil by a Novel Bacillus cereus Strain DRDU1 from an Automobile Engine

Abstract

Contamination of soil and air due to hydrocarbon is a global issue and bioremediation provides<br />probably the best way to remediate the contaminants. The current study shows the biodegradation of crude<br />oil, diesel and used engine oil by a newly isolated Bacillus cereus strain DRDU1 from an automobile engine.<br />Hydrocarbon degrading strains were screened on BH (Bushnell and Haas broth) agar supplemented with 2%<br />(v/v) of used engine oil as sole carbon source. The strain was found to be degrading 77%, 67%, and 16% of<br />diesel, crude oil, and used engine oil respectively after 28 days under nitrogen and phosphorus stressed<br />condition. It was increased significantly up to 99%, 84% and 29% in presence of nitrate and phosphate<br />supplements. Degradation was confirmed both gravimetrically and by gas liquid chromatographic analysis.<br />The strain proves itself a stress tolerating bacteria by withstanding 7% of salinity, 37% of glucose concentration<br />and 52% of relative humidity. The thermal death point of the strain was found to be 86oC. The significance of<br />the study is that the percentage degradation of the complex petroleum supplements used in the study was<br />found to be far higher than some of the previously reported values.