A. Degradation and Mineralization of Petroleum by Two Bacteria Isolated from Coastal Waters. B. Degradation and Mineralization of Petroleum in Sea Water: Limitation by Nitrogen and Phosphorus

Within the framework of a study on the oil biodegradation potential of the sea the ability of a Flavobacterium sp. and Brevibacterium sp. to metabolize a paraffinic crude oil and a chemically defined hydrocarbon mixture was investigated. Major components of the crude oil were identified by combination gas chromatography and mass spectrometry. The rate and extent of total hydrocarbon biodegradation was measured. Degradation started after a 2 to 4 day lag period, and reached its maximum within two weeks. At this time up to 60 of the crude oil was degraded. n-Paraffins were preferentially degraded as compared to branched chain hydrocarbons. Biodegradation and mineralization of petroleum, added at 1 vv to freshly collected sea water, were measured using gas-liquid chromatographic, residual weight, and CO2-evolution techniques. Only 3 of the added petroleum was biodegraded and 1 was mineralized in unamended sea water after 18 days of incubation. Added nitrate, phosphate supplements in combination increased petroleum biodegradation and mineralization. Attempts to clean up oil spills with the aid of microorganisms should take into consideration the nutritional deficiencies of sea water.