Selection and quantification of key functional genes of some selected bacterial species in a microcosms study for biodegradation of crude oil

Abstract GC-MS and qPCR have been used to facilitate the profiling of metabolites from a wide range of oil materials leading to the wide coverage of comprehensive central pathways involving primary metabolism and the quantification of functional genes responsible for the biodegradation of crude oil components. Therefore, the present study aimed to explore the ability of Pseudomonas aeruginosa and Pseudomonas lurida for the biodegradation of crude oil. The results of the GC-MS analysis showed an extensive elimination of hydrocarbons of mostly low and medium-chain hydrocarbons. The qPCR analysis was carried out to determine the activity of the functional genes and showed a substantially higher relative fold expression of 4-hydroxybenzoate monooxygenase gene (Ben) of 2.1x1014 fold after the first week (T1) during the biodegradation study with P. lurida. However, low relative gene fold of 60.91 for catechol-2,3-dioxtgenase gene (cat23) was observed. In the same vein, the relative fold expression of 2156.87 was detected for alkane monooxygenase (alkB) gene from a study with P. aeruginosa. This is substantially higher than the expression for cat23 gene and greatly lower than the Ben gene. The overall results of this study could evidently prove the environmental application of these bacterial species – B. endophyticus P. aeruginosa and P. lurida for the management of crude oil polluted environments. Hence, the overall finding from this study could be utilised as a tool to design an engineered bioremediation process to address the long devastating crude oil pollution across the Niger Delta and beyond.