Characterization of bacterial strains able to grow on high molecular mass residues from crude oil processing

Oil residues containing high molecular mass hydrocarbons, rich in polyaroma tic compounds, are frequent end-products of crude oil processing and are po orly biodegradable. Their disposal poses an environmental problem. Through batch-enrichments from contaminated soils we have isolated and characterize d seven bacterial strains that can use a residue from crude oil processing as a source of carbon and energy. The residue was a complex mixture of high molecular mass compounds, including saturated, aromatic and polycyclic aro matic hydrocarbons (PAHs). Analysis of the metabolic profiles of the strain s isolated showed that they could all metabolize long-chain-length alkanes efficiently, but not PAHs. Strains degrading naphthalene, a simple PAH, did exist in the soil inocula used, but could be isolated only when enrichment s were performed using pure naphthalene as the sole carbon source. All stra ins tested emulsified the oil residue and their ability to produce surfacta nts was studied. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.