Comparison of the fuel oil biodegradation potential of hydrocarbon-assimilating microorganisms isolated from a temperate agricultural soil

Strains of hydrocarbon-degrading microorganisms (bacteria and fungi) were i solated from an agricultural soil in France. In a field, a portion was trea ted with oily cuttings resulting from the drilling of an onshore well. The cuttings which were spread at the rate of 600 g HC m(-2) contained 10% of f uel oil hydrocarbons (HC). Another part of the field was left untreated. Th ree months after HC spreading, HC adapted bacteria and fungi were isolated at different soil depths in the two plots and identified. The biodegradatio n potential of the isolated strains was monitored by measuring the degradat ion rate of total HC, saturated hydrocarbons, aromatic hydrocarbons and res ins of the fuel. Bacteria of the genera Pseudomonas, Brevundimonas, Sphingo monas, Acinetobacter, Rhodococcus, Arthrobacter; Corynebacterium and fungi belonging to Aspergillus, Penicillium, Beauveria, Acremonium, Cladosporium, Fusarium, and Trichoderma were identified. The most active strains in the assimilation of saturates and aromatics were Arthrobacter sp., Sphingomonas spiritivorum, Acinetobacter baumanii, Beauveria alba and Penicillum simpli cissimum. The biodegradation potential of the hydrocarbon utilizing microor ganisms isolated from polluted or unpolluted soils were similar. In laborat ory pure cultures, saturated HC were more degraded than aromatic HC, wherea s resins were resistant to microbial attack. On an average, individual bact erial strains were more active than fungi in HC biodegradation. (C) 1999 El sevier Science B.V. All rights reserved.