It has been estimated that we only know perhaps less than 5% of all the bacteria species that exist in the world, mainly because we've either never tried to collect them, or they simply won't plate out on a nutrient medium (ie: agar).
When faced with a large oil spill such as the Exxon Valdez spill, naturally occurring bacteria in the ocean water and on the beaches will try to adapt to the changing conditions. Those bacteria that can best utilise the oil as a food source, will survive, populate and quickly dominate the immediate environment. The oil that they 'eat' will be used for both anabolism (building internal cell structures) and catabolism (generating heat and energy). However, the rate at which these naturally occurring bacteria can 'eat' the oil is dependent on the temperature and on the availability of nutrients - especially Nitrogen.
At temperatures below around 10 deg C., biochemical reactions start to slow down quite considerably. However, it is usually a lack of nutrients (especially N) in the sand or rocky foreshores which has the greatest rate limiting effect. Nitrogen is critical for the anabolic processes as all protiens are made from C N %26amp; O. The oil provides the C, and the air provides the O, but what provides the N?
In fact, one of the treatment methods involved injecting high N fertlisers into the sandy beaches in an attempt to make sure that N was not rate-limiting. This did in fact work - to a degree. The main problem with this method was that the N was free to move around and it got into non-poluted areas and caused algal blooms and eutrophication.
A number of other baterial methods have been tried at the Exxon Valdez spill site. Check the Batelle website (Washington State).
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