جاب الله, محمود2026-01-302026-01-302023-07-18https://dspace.omu.edu.ly/handle/123456789/517Crude oil spills pose a significant threat to various ecosystems, including soil ecosystems, necessitating the development of safe and efficient treatment methods. This study focuses on the bioremediation of soil oil waste through the utilization of indigenous bacteria capable of degrading hydrocarbon compounds, the primary constituents of crude oil. The aim is to convert these complex compounds into simpler and less harmful forms in the environment. Additionally, the study examines the combined efficacy of these bacteria under the same conditions. Representative soil samples were collected from oil-polluted sites in the Sarir and Sharara regions of Libya. Bacterial isolation and identification were conducted following established standards and protocols. Ten bacterial strains were isolated and tested for their ability to degrade crude oil by utilizing it as the sole carbon and energy source in a specific nutrient medium. The results demonstrated that Bacillus and Pseudomonas bacteria exhibited high efficiency in hydrocarbon degradation when working individually under the same conditions, with a significant effect observed (P>0.05). However, the efficiency decreased when these genera were combined in one medium, as Bacillus bacteria secreted antibiotics that hindered the growth and activity of other bacteria. These findings align with previous studies, highlighting the ability of these bacterial genera to decompose crude oil and convert it into less complex compounds under aerobic and/or anaerobic conditions, utilizing them as a source of nutrition and energy. We recommend utilizing these bacterial strains for environmental restoration through bioremediation of hydrocarbon-contaminated soils, particularly in similar regions where the strains are adapted to the local conditions. Furthermore, commercial applications of these strains are also viable.Bioremediation, Crude Oil, Hydrocarbons, Pseudomonas, Bacillus.Thesis