Degradation of petroleum hydrocarbons by facultative anaerobic bacteria under aerobic and anaerobic conditions

Nitrate-reducing bacterial strains (Pseudomonas sp. BS2201, BS2203 and Brev ibacillus sp. BS2202) isolated from petroleum-contaminated soil were capabl e of degrading petroleum hydrocarbons under aerobic and anaerobic condition s. Under aerobic conditions (a IO-day experiment in liquid media) the strai ns degraded 20-25% of the total extractable material (TEM), including up to 90-95% of all alkanes analyzed (n-C-10-C-35). Under anaerobic conditions ( a 50-day experiment) these organisms degraded 15-18% of the TEM, 20-25% of some alkanes, and 15-18% of selected polycyclic aromatic hydrocarbons. The strains also degraded saturated hydrocarbons under anaerobic conditions in the absence of nitrates as electron accepters. (C) 2000 Elsevier Science Lt d. All rights reserved.