How is bioremediation used to clean up oil spills?

Oil spill bioremediation uses hydrocarbon-degrading microorganisms to break down petroleum compounds. Approaches include: biostimulation - adding nutrients (nitrogen, phosphorus) to stimulate growth of indigenous oil-degrading bacteria; bioaugmentation - introducing specialized hydrocarbon degraders to supplement native populations; natural attenuation - monitoring natural degradation processes without intervention. Key organisms include Pseudomonas, Alcanivorax, Marinobacter, and various fungi. Oil components are degraded through different pathways: alkanes by beta-oxidation, aromatics by ring cleavage. Factors affecting success include oil type (lighter fractions degrade faster), temperature, nutrient availability, oxygen levels, and microbial community composition. Bioremediation is often combined with physical/chemical methods. The 1989 Exxon Valdez and 2010 Deepwater Horizon spills demonstrated bioremediation effectiveness.