Microbial Biodegradation of Aromatic Compounds in a Soil Contaminated with Gasohol

The studies developed in this work aimed to find alternatives to biodegradation or bioremediation of soils contaminated with gasoline or gasohol. So, the biodegradation of benzene, toluene and o-xylene (BTX) in soil samples contaminated with gasoline or gasohol by a bacterial consortium was studied. Four bacterial strains were selected for the consortium based on their growth capacity in gasoline, gasohol and BTX as sole carbon sources, and on the production of biosurfactants in mineral medium containing gasohol as the sole carbon source. The reduction of BTX concentrations in soil slurries in a multi-cell bioreactor system was used as the criterion to evaluate biodegradation efficiency. BTX removal was highly stimulated by air injection and mineral nutrients, and was significantly increased by the presence of the bacterial consortium. Addition of a proprietary oxygen release compound did not stimulate the biodegradation of BTX.