Oil pollution is considered one of the most significant environmental pollutants that negatively affect soil, water, and living organisms, particularly in oil-producing regions such as Iraq. This study was conducted in Kirkuk Governorate, where soil samples contaminated with oil were collected. Bacteria were isolated using a culture medium containing oil as the sole carbon source. The isolated bacteria were then identified based on their morphological, biochemical, and physiological characteristics, and their efficiency in crude oil degradation was evaluated using spectrophotometric analysis. 
The results demonstrated that Pseudomonas aeruginosa exhibited high degradation efficiency due to its ability to produce enzymes such as dioxygenase. In contrast, the isolate Bacillus subtilis showed a notable tolerance to harsh environmental conditions, although its degradation efficiency was lower than that of Pseudomonas aeruginosa.