CAPABILITY FOR DEGRADATION OF CRUDE-OIL HYDROCARBONS BY SEA-WATER MICROBIAL ASSOCIATION OF YEASTS AND BACTERIA FROM THE KVARNER BAY

A microbial association consisting of yeasts and bacteria, was selected from the autochtonous oil-degrading microbial community of oil polluted sea water near Rijeka Oil Refinery (Adriatic Bay of Kvarner). The enrichment was achieved by addition of crude oils as carbon sources to the sea water samples supplemented with nitrogen and phosphate. Bacteria and yeasts of the microbial association grown on crude oil and oil fractions, exhibited during cultivation a time-dependent sequential increase m number By the gas chromatography analysis, it was revealed that disappearance of n-paraffins from the crude oil was caused mostly by the activity of the yeasts in the association. Significant lowering of surface tension of the culture medium occured in the course of biodegradation of n-paraffins from the Angolan crude oil and during the cultivation of yeasts on glucose, probably owing to the production of biosurfactants.