Higher oil biodegradation potential at the Arabian Gulf coast than in the water body

Littoral materials collected from the intertidal zone along the coast of Kuwait City were associated with much higher numbers of oil-utilizing microorganisms than inshore and offshore water samples. Animate materials viz. epilithic biomass, cyanobacterial mats and roots of higher plants were richer in such microorganisms than inanimate materials, e.g. littoral sand, rock pieces, shells and others. Those numbers remained highest during the autumn, winter and spring and decreased dramatically during the hot summer. By far, the predominant indigenous oil-utilizing bacterium in the marine environment of Kuwait was Acinetobacter calcoaceticus. Less dominant organisms included Micrococcus sp., nocardioforms and others. Coast-immobilized strains of A. calcoaceticus and Micrococcus sp. had a higher hydrocarbon degradation potential than planktonic strains of the same organisms. It was concluded that marine coasts have a much higher potential for oil biodegradation than the water body. Received: 28 April 1999 / Accepted: 23 September 1999