The weathered hydrocarbons are mainly constituted of highly persistent heavy petroleum fractions. Thus, the soil chemical complexity delays the hydrocarbon biodegradation. The objective of this study was to increase the bioavailability of highly persistent compounds by obtaining the greatest nutritional conditions for indigenous microorganisms. A consortium was previously adapted in order to achieve the full potential of degradation through the biostimulation process which was carried out by the Plackett-Burman