BIOREMEDIATION OF OIL-POLLUTED SOILS USING INDIGENOUS MICROBIAL CONSORTIA ISOLATED FROM CONTAMINATED SITES IN NORTHWESTERN NIGERIA

Abstract

Oil pollution remains one of the most pressing environmental challenges in Nigeria, particularly in agricultural and semi-urban regions where crude oil leakage and spillage degrade soil fertility, threaten food security, and endanger public health. Conventional remediation strategies, though effective in some contexts, are costly, energy-intensive, and may lead to secondary environmental impacts. Bioremediation using indigenous microorganisms offers a more eco-friendly and sustainable alternative. This study investigated the bioremediation potential of microbial consortia isolated from crude oil-polluted soils in Northwestern Nigeria. Microbes were identified through enrichment culture, morphological, biochemical, and molecular techniques, with key isolates including aeruginosa, Bacillus subtilis, and Aspergillus niger. Microcosm experiments were set up to compare natural attenuation, single-strain treatment, and consortium inoculation. Results demonstrated that microbial consortia achieved the highest total petroleum hydrocarbon (TPH) reduction of 78% within 30 days, compared to 68% by single strains and 20% under natural attenuation. The synergistic interactions between bacteria and fungi enhanced degradation efficiency, particularly due to bio surfactant production and complementary enzymatic pathways. These findings suggest that indigenous microbial consortia hold significant promise as scalable, cost-effective, and environmentally friendly agents for oil spill remediation in Nigeria and beyond. Future research should focus on field-scale applications, optimization of environmental conditions, and integration into national environmental policies.