The number of bacterium in soil does not surprise me. I suspect that is a conservative number. I am doing some research that includes soil microbes and includes diatoms. You are absolutely right ! According to one of my sources there are over 10,000 separately identified diatoms alone, much less the other invertebrates. I will check out the Chakrabaty thread to see if I can identify which species would break down the petroleums. I am not interested in finding or adding GM biology to the soil at this point. I have a feeling that there are natural sources that consumes petroleum. I know of some species that live pretty deep in the earths mantle that consume methane, but have not researched what organisms might be able to survive closer to the surface.

Interestingly, there is a potential that new species might evolve at a higher trophic level as a result of the pollution of soil this close to the surface. Typically Methanophile organisms find food sources at depths that are protected from weather fluctuations that would kill them closer to the surface. The GM modification of these organisms may also produce a "natural" self propagating population for future generations. It will be interesting to follow the technology and watch human induced evolution in progress.