Isolation of oil-degrading bacteria was done using Natural Sea Water (NSW)-oil media. The chemical composition of the oil, temperature, oxygen and nutrients were correlated with bacterial degradation of the hydrocarbon.

Six bacterial isolates possibly from the genera Pseudomonas, Alcaligenes, Bacillus, Brevibacterium, Corynebacterium, and Micrococcus were characterized based on morphology and biochemical test.

The bioremediation potential of the isolate was determined by measuring the percentage of oil conversion. The bacterial isolates degraded a greater percentage of motor oil as hydrocarbon substrate in the medium as compared with diesel oil. Anova and t-distribution analysis showed that the values obtained for biodegradation potential were highly significant.

Key words: oil-degrading bacteria, bioremediation, Manila Bay, Pseudomonas, motor oil