Short-term study of biological degradation of diesel oil by bacteria isolated from petroleum-contaminated soil

Abstract

The use of fossil fuels leads to environmental contamination during their extraction, processing and distribution. Microbial biodegradation provides a sustainable method for cleaning contaminated areas which follows the principles of sustainability. This paper presents the dynamics of biodegradation of hydrocarbon fractions of diesel oil, using Planomicrobium sp. and Rhodococcus sp. isolated from petroleum-contaminated sites. GC–MS analysis was employed to analyse abundances of the specific compounds such as n-alkanes, isoprenoids, sesquitepranes, hopanes, steranes and aromatic compounds (naphthalene and its methylated homologues, phenanthrene and anthracene and their methylated homologues, and dibenzothiophene and its methylated homologues). The obtained results showed that after 30 days of biodegradation of diesel, a significant degradation was achieved, with almost complete degradation of n-alkanes and a decrease in the amount of sesquiterapanes. Rhodococcus sp. had a higher efficiency in degradation of n-alkanes, while Planomicrobium sp. had a higher efficiency in the degradation of branched hydrocarbons. Both strains showed high activity in the biodegradation of sesquitepranes and demonstrate ability to degrade methylated phenanthrenes. Additionally, dimethyl-dibenzothiophenes were almost completely degraded and removed from the system. This study presents the first comprehensive report on the GC–MS analysis of the diesel biodegradation pattern of the Planomicrobium sp., compared with the well-established Rhodococcus sp.