التقنية الحيوية ودورها في معالجة التربة الملوثة بالنفط الخام بواسطة البكتيريا

Abstract

Bioremediation is a natural process in which microorganisms alter and degrade the structure of petroleum hydrocarbon compounds into other substances. The resulting compounds, such as carbon dioxide, water, and biomass, may be partially oxidized due to biological transformation. The bacteria that consume petroleum are referred to as “hydrocarbon-oxidizing bacteria” because they oxidize these compounds, leading to their degradation and the transformation of contaminated soil into clean soil. This study was conducted to evaluate the efficiency of biotechnological methods using bacteria to remediate oil-contaminated soils. The experiments were carried out in the microbiology laboratory at the Oil Research Center using soil samples from the crude oil-contaminated area of the Zawiya Refinery, with contamination originating from the Sharara oil field . The study concluded that a high percentage of hydrocarbon degradation and breakdown was achieved—up to 60%. The bacterial strains (Actinomycetes, Pseudomonas aeruginosa, and Vibrio) demonstrated very high growth capacity in the contaminated environment. The efficiency of the bioremediation process was found to be directly proportional to the active biomass in the soil. Similarly, hydrocarbon degradation was positively correlated with time, particularly during the initial phase of biodegradation by hydrocarbon-oxidizing bacteria. This process is facilitated by the enzymes produced by these bacteria, capable of degrading polycyclic aromatic hydrocarbons (PAHs). Most of the isolated bacterial strains were Gram-negative, characterized by a lipid-rich outer membrane. This feature enables them to absorb a greater quantity of hydrocarbon compounds from the environment, subsequently oxidizing and utilizing them as a carbon source