Systematic Intrinsic Biodegradation Studies of Crude Oil Contaminated Soil of Bdere Community in South-South, Nigeria

Abstract

Crude oil pollution is a perennial environmental menace that has bedevilled the South-South ecosystem of Nigeria. This study was aimed at using gas chromatography-mass spectrometry (GC-MS) technique to investigate the biodegradation capabilities of nine bacterial cultures on crude oil residues in Bdere area in South-South, Nigeria. These microorganisms include Pseudomonas aeruginosa, Bacillus subtilis, Bacillus cereus, Micrococcus spp, Pseudomonas putida, Clostridium spp, Bacillus spp, Streptococcus spp, and Serratia spp. The results from the microbial-degraded samples were compared with an abiotic control. The findings reveal that the total petroleum hydrocarbon (TPH) in the microbial-treated samples was significantly attenuated compared to the control, confirming the microrganism's ability to degrade crude oil components. The primary degradation pathway involved biological oxidation of the aliphatic hydrocarbons, transforming them to primary alcohols, aldehydes, and fatty acid derivatives. Degradation was also observed across a wide range of short and long-chain alkanes, aromatic hydrocarbons, and polycyclic aromatic hydrocarbons (PAHs). However, some resistant compounds persisted, and certain degradation products inhibited the rate of further biodegradation. The generation of new metabolites and intermediates confirmed the effective microbial remediation. These findings expand our understanding of microbial degradation of hydrocarbons, offering potential strategies for environmental remediation of oil-contaminated sites.