Biodegradation of diesel D2 by indigenous Rhodococcus sp. recovered from petroleum contaminated soil

Diesel has served as a primary source of fuel in transportation, as well as in small-scale energy generation for backup or emergency power supply, for decades (de Witt et al, 2021). Despite the decreasing production of fossil fuels due to global energy transitions, environmental contamination by petroleum derivatives can persist for extended periods (Marigómez, 2014). Consequently, there remains a high demand for improved technologies to clean up contaminated areas [Ossai et al, 2020]. This paper presents a GC/MS study on the biodegradation of hydrocarbon fractions of diesel D2, utilizing indigenous Rhodocuccus sp. isolated from petroleum-contaminated soil. GC-MS analysis was employed to determine the abundances of specific compounds such as n-alkanes, isoprenoids, sesquiterpanes, hopanes, steranes, and aromatic compounds (including trimethyl-naphthalenes, phenanthrene, anthracene, methylphenanthrenes, dibenzothiophene, and methyl-dibenzothiophenes). After 30 days of biodegradation of diesel D2, significant degradation was achieved, with complete degradation of sesquiterpanes and a reduction in the number of n-alkanes lower than C21. Pristane and phytane were almost completely degraded. Additionally, dimethyl-dibenzothiophenes were nearly completely degraded and removed from the system.