Environ Exp Biol (2015) 13: 13–18

Isolation and identification of oil degrading bacteria from oil sludge in Abadan oil refinery

Abstract

Oil sludge, a rich source of hazardous pollutants that cause soil and water pollution, can be treated by biodegradation. The aim of this study was isolation of native bacteria from oil sludge produced in Abadan refinery, Iran. Native bacteria were isolated and screened based on their potential in reduction of total petroleum hydrocarbons, hemolysis, oil spreading technique and gas chromatography analysis. They were identified by 16S rRNA sequencing. Optimum N and P sources were also investigated. Pseudomonas stutzeri AOR₁, through biosurfactant production, and Klebsiella pneumoniae AOR₂, via degradation of long chain hydrocarbons, had the most potential in oil recovery. NaNO₃ and Na₂HPO₄ were the optimum N and P sources for P. stutzeri, and NH₄Cl and (NH₄)₂HPO₄ for K. pneumoniae. It can be concluded that the introduced bacterial isolates have great potential in oil recovery from oil sludge, which makes them candidates for biodegradation and bioremediation purposes.