Biodegradation of PAHs in drilling wastes from oil-contaminated soil using an isolated halotolerant bacterial consortium

Abstract

Petroleum contaminants and fossil fuel activities contribute significantly to environmental pollution, especially in regions involved in oil production. Polyaromatic hydrocarbons (PAHs) in petroleum products are hazardous to the environment and human health because of their intricate chemical makeup and cancer-causing characteristics. In this study, we isolated and characterized bacterial strains from oil-contaminated soil using 16S rRNA analysis to evaluate their potential for degrading PAHs commonly found in drilling wastes. We also analyzed the PAH content in drilling cuttings and assessed the effectiveness of PAH biodegradation by the isolated bacterial consortium on real oil-drilled cutting samples. Additionally, a bioremediation consortium comprising Pseudomonas stutzeri, Pseudomonas aeruginosa, and Bacillus subtilis was used to remediate PAHs. This study suggests that indigenous bacteria contribute favorably to the process of PAH biodegradation. We observed that benzo(a)anthracene exhibited the fastest degradation rate among the tested compounds, while fluorene showed slower degradation than the other tested compounds. Importantly, the efficiency of all tested scenarios surpassed 97%, highlighting the efficacy of the bioremediation approach in reducing PAH contamination. These results underscore the potential of utilizing bacterial consortia for effective PAH remediation, contributing to the development of sustainable strategies for environmental remediation.