Interaction of aerobic and anaerobic bacteria in petroleum biodegradation

Abstract

The relationships between aerobic petroleum-degrading and anaerobic sulfate-reducing bacteria in oil degradation are presented. Neither pure nor mixed cultures of sulfate-reducing bacteria were able to grow on oils under anaerobic conditions. Such cultures, however, were able to grow on the residues from the aerobic bacterial degradation of some oils. Growth of sulfate-reducers was determined in part by the nature of the aerobic population used to degrade an oil, the chemical composition of the oil and whether the sulfate-reducing bacteria were in pure or mixed cultures. If mixed cultures were grown, then a nitrate-free medium had to be used because of the production of nitrate by mixed cultures. The results presented support the hypothesis that sulfate-reducing bacteria cannot initiate degradation of oil but rather grow on the residues resulting from the aerobic degradation of oil.