Environmental contamination by diesel fuel poses substantial ecological challenges, compromising both terrestrial and aquatic ecosystems due to its persistent toxic properties. Biological remediation offers a sustainable and environmentally conscious solution to address these environmental concerns by utilising hydrocarbon-metabolising microorganisms. This research examines the bioremediation capabilities of Paenibacillus polymxa, obtained from a diesel-polluted location, for addressing diesel contamination issues. The isolated bacterial strain developed prominent, cream-coloured, textured colonies when grown on Bushnell-Haas medium and exhibited elongated, Gram-positive, motile characteristics with spore-forming capabilities. Biochemical analysis demonstrated broad metabolic capabilities, showing positive responses for catalase, oxidase, urease, casein degradation, and starch breakdown activities. Maximum diesel breakdown efficiency was observed at 5% diesel concentration, pH 9, and 37°C temperature, achieving a peak degradation rate of 70%. These results demonstrate the organism's durability and effectiveness in hydrocarbon metabolism, establishing it as a viable option for environmentally sustainable remediation of diesel-contaminated areas. Subsequent research should emphasise genetic optimisation, nutrient enhancement, consortium development, and field validation to confirm practical applications and commercial viability
